We pick the 15 best deals the past 10 years - excluding frees - taking a player's price, performance, success and sell-on value into account.
The last decade has seen plenty of signings - some good, some bad and some ugly - and we are here to go through the very best.
From 15 to 1, and featuring the likes of Kante, Sadio Mane and Eden Hazard, let's take a look at the full rundown...
15. Alisson: Roma to Liverpool (€72m)
He might be the most expensive goalkeeper of all time, but Alisson has backed up his enormous price tag since arriving from Italy. Arguably the missing piece of the Jurgen Klopp jigsaw, the Brazilian shot-stopper has given the Reds some much-needed assurances at the back and played a big part in their Champions League triumph last season.
Ending his first Premier League campaign with 17 clean sheets and the golden gloves too, Alisson's price tag has quickly been forgotten by the Anfield faithful.
14. David Silva: Valencia to Manchester City (cost €29m)
Since arriving from Valencia in 2010, David Silva has been at the heartbeat of Manchester City's emergence as a Premier League heavyweight. The midfielder's adaptability and all-round play has been a cornerstone for City's success over the past decade with his influence far exceeding the €29 million it cost to bring him to the Etihad.
While often overlooked for individual awards, Silva has always been a team player and will take some serious replacing next season.
13. Sancho: Manchester City to Dortmund (€8m)
One of the most in-demand footballers in the world right now, Borussia Dortmund picked up an almighty bargain in Jadon Sancho.Signed for just €8 million from Manchester City in 2017, Sancho has gone on to shine in the Bundesliga and has already established himself in England's national team.
The 19-year-old helped secure Dortmund the DFL Supercup earlier this year with a goal and assist in a 2-0 win over Bayern Munich - in the process cementing his status as one of the game's brightest prospects. Sancho now looks certain to be sold in the coming months for a near nine-figure sum, making him a very shrewd investment for Dortmund.
12. Kroos: Bayern to Real Madrid (€25m)
Described by Zidane as Real Madrid's "missing link" in 2015, Toni Kroos has gone on to justify Zizou's big claim and brings the side together on the pitch.
The German midfielder has helped guide Los Blancos to three Champions League crowns and one La Liga title since his arrival from Bayern Munich in 2014 for a less than sizeable fee by today's standards. Kroos' range of passing and vision is up there with the very best in Europe and at 29, he can continue to be key for Real for years to come.
11. Ter Stegen: Monchengladbach to Barcelona (€12m)
After a shaky start at Camp Nou following his move from the Bundesliga, Marc-Andre Ter Stegen has gone on to establish himself as one of Barcelona's most important players.The past two seasons have been particularly impressive from the German shot-stopper as he does his best to make up for a leaky Catalan defence.
To add yet another feather to his cap, Ter Stegen is now showing plenty of skill with the ball at his feet and already has two assists to his name this La Liga campaign. With a world-class keeper costing close to nine figures in the current market, Barca's acquisition of Ter Stegen in 2014 has aged very well after initial concerns.
10. Kante: Caen to Leicester City (€9m)
The Frenchman was a rock in the Foxes' side as they claimed a shock Premier League title in 2016 with Kante topping the domestic charts for both tackles and interceptions that season. Chelsea inevitably came calling the following campaign, shelling out £35m for Kante, as Leicester were left to reflect on a terrific, albeit short-lived transfer.
9. Godin: Villarreal to Atletico (€8m)
Considering Atletico Madrid's style of play this decade, it's no exaggeration to say Diego Godin has been the club's trusty foundation for most of it. The Uruguayan centre-back was key in cementing Diego Simeone's strong defence, with Godin himself going on to star individually. He was named La Liga's best defender in 2015-16 while also being selected in the Champions League squad of the season three times.
While Atletico let him go for free over the summer, what he gave them over nine seasons far exceeded the €8 million they paid to Villarreal in 2010. During Godin's time in Madrid, he played a pivotal part as the club claimed two Europa League titles, one La Liga crown and made two Champions League finals.
8. Mane: Southampton to Liverpool (£34m)
Considered unlucky by some to miss out on the Ballon d'Or this year, it can't be doubted just how good Sadio Mane has been for Liverpool. Joining from the Saints in 2016, the Senegal international has been a fundamental part of Jurgen Klopp's frontline, playing a key part in the club's Champions League success last season.
A joint winner of the Premier League's golden boot last campaign, Mane's firepower and work rate is hard to rival. Seen by some as a gamble a few years ago, the 27-year-old is now one of the most reliable goalscorers around as he continues to drive the Reds towards a first league title since 1990.
7. Vardy: Fleetwood Town to Leicester City (£1m)
From the fringes of English football to centre stage, Jamie Vardy took the Premier League by storm in 2015-16 as he fired Leicester City to the Premier League title.
His 24 goals that season cemented a surprise title for the Foxes and the striker hasn't stop scoring since. Currently leading the golden boot race this season, Vardy continues to highlight just what a shrewd signing he was by Leicester back in 2012.
6. Aguero: Atletico to Manchester City (€40m)
He might not have come cheap in 2011, but Sergio Aguero's price tag was very quickly forgotten at the Etihad and he's gone on to continue providing amazing value in front of goal for Manchester City.From scoring on debut, to his unforgettable strike that secured City the Premier League title in dramatic circumstances in 2011-12, the Argentine took just one season to repay his transfer fee and then some.
Three more domestic titles have followed courtesy of Aguero's goals, with the striker only once failing to score 20 or more goals in a single season for City since his arrival at the club.
5. Hazard: Lille to Chelsea (€35m)
After a stellar final Ligue 1 season with Lille, Eden Hazard was brought to Stamford Bridge in 2012 for €35 million. In the seven seasons that followed, the Belgian would become the club's undisputed star, proving key as the Blues won two Premier League titles, two Europa League crowns and one FA Cup.
In 2019, Chelsea then allowed Hazard to fulfill his dream move to Real Madrid and pocketed a cool €100m in the process - a very handy profit for a player that provided so much.
4. Modric: Tottenham to Real Madrid (€35m)
Signing a future Ballon d'Or winner for just €35 million today would be the deal of any club's dreams and that's just what Real Madrid realised with their acquisition of Luka Modric in 2012.
The Croatian wasted no time becoming integral to Real's squad, twice voted La Liga's best midfielder, before winning the Ballon d'Or in 2018. Los Blancos' four Champions League titles since Modric's arrival have been no coincidence either with his incredible work rate and range of passes opening the door for the club's attacking stars to shine and conquer in Europe.
3. Mahrez: Le Havre to Leicester City (€500,000)
After a less than stellar career in Ligue 2, Leicester City took a gamble on Algerian Riyad Mahrez in 2014 and hit the jackpot. Helping seal the Foxes' promotion to the Premier League, the pacey attacker then played a crucial role in the club's stunning 2015-16 season scoring 17 league goals as they sealed the English top-flight title.
Two more solid, if not as spectacular seasons would follow before Leicester cashed in on their asset to the tune of a £60 million fee from Manchester City. A stunning profit and a surprise piece of silverware make Mahrez one of the bargain buys of the decade.
2. Varane: Lens to Real Madrid (€10m)
Four Champions League crowns, two La Liga titles and one World Cup; the career of Raphael Varane has become synonymous with success since his move to Real Madrid in 2011.
Arriving for a modest fee of just €10 million from France, the centre-back has played a key role in defence for an all-conquering Real side over the past decade. You only need to look at Liverpool's acquisition of Virgil van Dijk to realise the importance of a quality centre-back and what a steal Varane was for Los Blancos.
1. Salah: Roma to Liverpool (€42m)
Given their struggles to meet UEFA's Financial Fair Play (FFP) regulations, Roma were left with no option but to cash in on star forward Mohamed Salah before June 30, 2018.Liverpool exploited the situation superbly, persuading the cash-strapped Giallorossi to let the Egyptian move to Anfield for an initial €42m (£36.9m).
However, even the Reds couldn't have imagined just how big a bargain Salah would prove to be, with the winger breaking the Premier League goalscoring record for a single, 38-game season in his first year on Merseyside before helping Jurgen Klopp's side win the Champions League last term.
Honourable mentions
It's been a busy decade in the transfer market and a number of successful buys have narrowly missed out on our final list.
Virgil van Dijk was unlucky not to join his Liverpool team-mates Alisson, Salah and Mane in the top 15, having completely transformed the Reds' defence since his arrival from Southampton for £75m ($98m).
Luis Suarez's move to Barcelona has also been a success, but he didn't come cheap either so just missed out.
In terms of bargain buys, Dusan Tadic to Ajax and Serge Gnabry to Bayern Munich both deserve a special mention.
winningTiger
2689
When you realise Nicolas pepe 72million could have bought 8 Ngolo kantes[Crylaugh] 144 Riyad Mahrez
72 jamie vardys
raynknight
958
from being voted as worst Signing of year of La LiGa in 2012 to winning Ballon D'or in 2018 🌟 what a player and what a signing 👊
Mesballer
536
Leaving out Zlatan Is A Punishable Offense 😂😂😁
Nadan7
529
When life gives you Valverde as a Coach, make his a midfielder “maestro “🔥🔥
Futbolista
453
Hey guys! I know it’s unrelated to the topic, but these users keep making lies about me and bothering me with non-football and insulting conversation. I’m feeling attacked.
lukzlat910
408
This was the best bargain of this season, an exceptional talent for just 15 million from a Championship club and has established himself into the first team at a big club, Dan James the Flash
raynknight
359
Came as a Backup and cemented as one of BarCa's Best ever GK 🌟 what a Transfer and what a wall 👊
raynknight
343
Best Transfer paper aka Napkin of all Time 🌟
Nadan7
306
🦁Transfer 🦁in other words means Zlatan 🦁🦁
mzeereal
247
Modric went from grass to grace and become world champion,wining golden ball and vital trophies.. Salah went from grass to grace and become world class player and won the fans heart around the globe..Mane went from low class player to classic player with humble soul..Varane become the most luckiest of all with champions league and world cup in same year..Hazard moved from best player to classic player among the world best player..Alisson the unbelievable signing become wonderful player and won major trophies
Nadan7
234
The best breakthrough academy player in the decade TAA ( corner taken Quickly)
Mesballer
200
Best Transfer of the Decade VAR Free Transfer to Tottenham Trophies Free transfer to Liverpool
Nadan7
188
Allison should be No. 1 ... This save vs Napoli costed Barcelona 4 trophies 🏆 🏆🏆🏆
Nadan7
185
In 2013 Barcelona signed Neymar from santos and the rest is MSN destroyer defenders and goalkeepers in the decade 🔥🔥
intelligency44
114
What about David De Gea €25M from Atl. Madrid to Manchester united. Becoming the English premier league goalkeeper of the decade. He has save man united countless times.
raynknight
64
Lewandowski's Transfer form Dortmund to Bayern 🌟 Cost - £0 what a player and what a transfer 👊 Mr. BundesliGa 🌟