Some can arrive on a free that have not worked out (Joe Cole, Liverpool), while others have had huge misfortune with injury (Hatem Ben Arfa, Newcastle) but sometimes there is just no excuse.
Here Sportsmail lists the 10 biggest flops that have left supporters tearing their hair out over the course of this season.
Bebe (Manchester United, ?7.4m from Vitoria Guimaraes)
If Javier Hernandez is up there with the finest of United signings, then Bebe must also be in with a shout of being one of Sir Alex Ferguson's worst.
Over the odds: Man United paid ?7.4m for Bebe, despite Sir Alex Ferguson having never seen him play
Fergie had never even seen him play before agreeing a deal which didn't help and only added more expectation on the player to become an overnight superstar.
After seven average performances mostly against lesser opposition, the Portuguese midfielder hasn't featured since being hustled out of the game by Conference side Crawley Town in the FA Cup at Old Trafford.
The 20-year-old has time to bounce back but there has been very little sign of the supposed talent that forced United to pay way over the odds.
Fernando Torres (Chelsea, ?50million from Liverpool)
After an average first half of the season with Liverpool it was thought Torres's mood and form would perk up a bit when he joined a side fighting for the title.
Bad to worse: Fernando Torres' season failed to improve at Chelsea
Instead it has got worse, just one goal against bottom side West Ham is all the striker has to show for smashing the British transfer record and rarely has he managed to have a major influence on games.
Whether the 27-year-old is played on his own, with Didier Drogba, with Nicolas Anelka or both, it just hasn't worked and Chelsea face one hell of a job trying to find a system that is comfortable with the Spaniard.
For half of the money the Blues could have brought Darren Bent.
Christian Poulsen (Liverpool, ?4.5million from Juventus)
A dream move to Liverpool has turned into a nightmare for Poulsen who has become one of the symbols of Roy Hodgson's ill-fated reign at Anfield.
Out of favour: Christian Poulsen has not featured for two months
Often caught in possession, poor with his passing and ineffective in the tackle, he just couldn't adapt to the Premier League. Once fans quickly turned on the Dane it was downhill from there.
Not even under new boss Kenny Dalglish could the 31-year-old show any type of form and he has not featured since a 1-0 defeat in Braga two months ago. Almost certain to leave the club in the summer.
Paul Konchesky (Liverpool, undisclosed from Fulham)
A crucial part of Hodgson's Fulham team but a big misfit at Liverpool. A string of poor performances quickly made the left-back a target for irate fans up in arms over Hodgson's tenure at Anfield, with his last game coming in a 3-1 defeat at Blackburn in January.
Scapegoat: Paul Konchesky's form symbolised Roy Hodgson's regime at Liverpool
That's because Kenny Dalglish then took over and decided he was so bad he would even put a right-back in his place instead - shipping the 30-year-old off to Nottingham Forest for the rest of the season.
He is unlikely to play for Liverpool again and that's before you mention his mother's facebook rants about the club's fans.
Mauro Boselli (Wigan, ?6m from Estudiantes)
The gamble that has backfired in a big way for Roberto Martinez. Boselli became the club record signing after arriving from Argentina with an impressive scoring record and was charged with leading Wigan's goal-shy strike force.
Disaster: Wigan's record signing Mauro Boselli failed to score a league goal
But a combination of struggling to settle and a lack of form and confidence quickly made him a weak link in the team to the point that even fellow flop Franco di Santo could get a game ahead of him.
With just one Carling Cup goal to his name, Martinez lost patience and packed him off to Genoa for the rest of the season where he has scored just twice.
Stephen Ireland (Aston Villa, player exchange from Manchester City; Newcastle, loan from Aston Villa)
No one knows exactly when he walked under a ladder and broke a mirror at the same time but Ireland's season has been a shambles from the very start.
Nightmare season: Stephen Ireland has struggled with injuries and loss of form
A pawn that involved him and James Milner switching clubs, the 24-year-old's first game for Villa was a disaster as he started in the 6-0 defeat at Newcastle. Things only got worse when Gerard Houllier took over as he was gradually frozen out of aside that failed to win a Premier League game he started.
Newcastletook him on loan until the end of the season in January but injuries have restricted him to just 49 minutes of football at St James' Park.
Edin Dzeko (Manchester City, ?27m from Wolfsburg)
HavingCarlos Tevez, Mario Balotelli and David Silva in attack wasn't enough for City boss Roberto Mancini who decided the free-scoring Bundesliga striker was the man to fire City towards the Champions League.
Slow start: Edin Dzeko (left) has failed to live up to his price tag
And Europe's elite is where City will be next season but that is more in spite of the Bosnian who has scored just one league goal since arriving at Eastlands - albeit a crucial winner at Blackburn.
Given the chance ahead of Balotelli or the injured Tevez, the 25-year-old has struggled to stamp his authority in attack and often finds games passing him by as if he is an innocent bystander. Needs to improve next season.
Sebastien Squillaci (Arsenal, ?6.5m from Sevilla)
Out went Sol Campbell and William Gallas, in came ?10m Laurent Koscielny and Squillaci. Arsenal's defence has looked like an accident waiting to happen ever since.
French flop: Sebastien Squillaci (left) has been woeful this season
Koscielny has time to improve but at 30-years-old, Squillaci should be at his best but rarely has he shown any sort of leadership qualities that Arsenal have been crying out for at the back this season.
The Frenchman is easily beaten in the air and has often been caught playing a striker onside. Hard to see him finding a place in the starting XI next term with the return of Thomas Vermaelen from injury.
Pablo Barrera (West Ham, ?4m from Pumas)
After making a promising impact at the World Cup for Mexico, the Hammers looked like they had found a creative wide man in Barrera that could help spoon-feed chances for their strikers.
Great expectations: Pablo Barrera starred at the World Cup for Mexico
A speedy winger who could use both feet, the 23-year-old was tracked by Everton, Manchester United and Tottenham before arriving at Upton Park - but he soon lost all that once he put a claret and blue shirt on.
Easily marked out the game and often wayward with his final ball (if he managed to get that far), the Mexican hasn't featured in the Premier League since January.
Robbie Keane (West Ham, loan from Tottenham)
A proven goal scorer with a handy knack of creating chances out of nothing was exactly what West Ham were looking for in January - instead they got Robbie Keane.
In decline: Robbie Keane is a shadow of the player he once was
The Irishman has been in a decline since leaving Spurs for Liverpool in 2008 but a chance to play regular football again at Upton Park seemed to suit both parties in getting their respective seasons back on track.
Instead the 30-year-old's high wages came at a return of injuries and a host of crucial missed chances that have not only accelerated West Ham's down fall but have been a catalyst towards his own.
Little Pea set for big future at Manchester United, says RioVan der Vaart pledges future to Spurs despite Champions League failureScotland striker O'Connor arrested over alleged cocaine possession in Edinburgh
Explore more:People: Alex Ferguson, Hatem Ben Arfa, Sol Campbell, William Gallas, Robbie Keane, Paul Konchesky, Kenny Dalglish, Christian Poulsen, David Silva, Fernando Torres, Gerard Houllier, Mario Balotelli, Edin Dzeko, Darren Bent, Didier Drogba, Carlos Tevez, Bebe, Joe Cole, James Milner, Roy Hodgson, Thomas Vermaelen, Roberto Mancini, Laurent Koscielny, Nicolas Anelka, Roberto Martinez Places: Liverpool, Newcastle, Argentina, Ireland, Mexico, Europe