Every fan hopes their club can produce the best signing of any transfer window. Sometimes a new arrival can indeed prove to be a masterstroke but sometimes that latest signing can of course also develop into an expensive mistake.
Managers are therefore desperately attempting to complete the right pieces of business before Friday at 11pm brings the end of this January's transfer window. But what do you think of the big-name signings which have been completed?
From the loans to the mega-money, we have rounded up all the information you need on the key moves, including the details on the player's background, his strengths and weaknesses, opinion from around the world and expert analysis. Get the lowdown and then vote on whether the signing will be a Hit or Miss.
Click on the individual players below to vote Hit or Miss and have your say...
Kim Kallstrom's injury in his first training session with Arsenal is a big blow. He has enjoyed a good career and has the technical capabilities as well as the attitude to thrive. Mathieu Flamini has shown that underwhelming additions can make a significant contribution and Gunners fans would be well-advised not to underestimate the Swede. Bodies will be needed if Arsenal are to compete in three competitions during the second half of the season so they will hope his injury is not too serious. Will his loan from Spartak Moscow be a success at Emirates Stadium?
After joining Crystal Palace, who were the busiest Premier League club on deadline day, on loan just before 11pm, Thomas Ince will now add some more attacking threat. The Blackpool winger has that little bit of an 'X factor' to surprise defenders and will give Palace that extra spark for Premier League survival.
Lethargy in front of goal has been a problem for Fulham this season but there seems little danger of that with Kostas Mitroglou. The Greece international is one of the in-form strikers in European football and bagged a Champions League hat-trick as recently as October in the 3-0 win at Anderlecht. This is a player who could link up well with Lewis Holtby and turn Fulham's season around.
Despite having spent enough of Roman Abramovich's money to make Chelsea the biggest spenders in January to date, Jose Mourinho has repeatedly tried to sell the message of his acquisitions being responsible in terms of the long-term 'project' he's overseeing. To this end, Zouma's age versus potential fits the bill perfectly. "We liked the profile; we think he's very much adapted to the Premier League. He is a young player for a position where we also need the future," said Mourinho of his latest addition.
John Heitinga lost his place in the Everton team for a reason but he will be keen to prove a point at Fulham and a player with the experience of playing in a World Cup final, regardless of his sending off, must be viewed as a bonus in a relegation scrap. Fulham have had a good deadline day and Heitinga is surely an upgrade on Philippe Senderos.
Hennessey has proven he can perform in the Premier League and at 27 should be coming into his prime years as a goalkeeper. He has height, agility and can kick the ball well with either foot. With Julian Speroni turning 35 in May, it would be no surprise to see Hennessey establish himself as the Eagles No 1 before too long. But is he better than the incumbent? And aren't there better ways to spend £3million?
What's not to like? A member of Germany's golden generation heralded as a superb capture for Tottenham just one year ago now finds himself at lowly Fulham. This has coup written all over it. Already handed the prized No 10 shirt, it seems Rene Meulensteen has big plans for Holtby and is willing to build the team around him. That's the sort of attention that Holtby was denied at Spurs and could see him bounce back to his best. Or will it?
Cardiff desperately need a little pazazz to complement what is a hard working unit but one that is severely lacking in terms of invention in the final third. Zaha's choices in matches can lack maturity but there's no doubt he can get supporters off their feet and if Ole Gunnar Solskjaer can get him flying on the left and Craig Noone doing likewise on the opposite flank, there's every chance a winless run of seven matches can be arrested. The Norwegian has said of his new signing: "He has pace, power, technical ability and goes past people. He will give us that extra change of tempo in the final third, where we really need it. He will bring that little final bit to find pockets of space and produce a bit of magic."
Tony Pulis was determined to add numbers to his squad on a busy deadline day for Crystal Palace and in Joe Ledley he has acquired a player with European experience and the nous to have a positive impact on everyone around him.
A popular figure at Brighton, Bridcutt's passing and tackling are of Premier League quality and he is an impressive player with and without the ball. But the 24-year-old could be a significant dressing room influence too given his unique understanding with Gus Poyet. The new Sunderland boss is working to transform the team's approach and nobody knows the manager's intentions quite like the midfield conductor from his Brighton days. But is it an unnecessary risk placing him at the heart of their plans?
Having gazumped Liverpool for the signing of Mohamed Salah from Liverpool, Chelsea were clearly intent on getting a player dubbed the 'Egyptian Messi'. With the money from the sale of Juan Mata burning a hole in their pocket, it is perhaps not that biggest gamble for Chelsea but Salah is still only 21 and was not a regular in Basel's first team. However, the versatile winger has pace in abundance and demonstrated his counter-attacking qualities when scoring home and away against Chelsea in this season's UEFA Champions League.
"He is someone who can bring something special around the box that we are missing," claims Sunderland boss Gus Poyet. "He is comfortable in a front three but we will use him further up the pitch because he is not really a defensive player. We need to score goals and Scocco could provide us with that little bit extra both in scoring goals and creating them." But he'll have to adapt to the English game rather better than he did to life in Brazil.
With Arouna Kone injured and Nikica Jelavic sold, there is scope for a striker to make an impact at Goodison Park. Traore was building quite a reputation for himself prior to the upheaval of the past six months and will be anxious to make up for lost time as he bids to impress ahead of the World Cup in the summer. Can he do the business for Everton or will he be little more than back-up for Romelu Lukaku?
Given the loan from Borussia Monchengladbach is with a view to a permanent move, Newcastle United have an easy way out if the switch does not work and Luuk de Jong continues the form which has seen him fail to score so far this season. But there is a huge upside to the deal if De Jong can get back to the goalscoring which saw him net 32 times for FC Twente in the 2011/12. De Jong will need to hit the ground running but Newcastle require a successful forward.
William Kvist brings with him a combative approach that has been somewhat lacking from Fulham's performances so far this season and will provide support for the ageing trio of Scott Parker, Giorgos Karagounis and Steve Sidwell in midfield. Kvist has good experience in the Bundesliga and, arguably more importantly given the sated egos among the Cottagers playing staff, a point to prove. But will a temporary signing from Germany have the transformative impact that is required of a team that is now the bookmakers' favourites for relegation?
A 2-0 win at home to bottom-club Cardiff City is not going to have the rest of Europe in a panic regarding a Manchester United revival just yet but this was that start - and the sight of Juan Mata stroking the ball around in the midfield was more than enough to cheer the Old Trafford crowd. There was nothing particularly exotic about the reality. "I tried to make him play in a position where he was not comfortable," Jose Mourinho admitted upon Mata's exit from Chelsea. But Moyes doesn't appear to be ready to take that kind of £37million risk as Mata settled into his favoured No 10 role against Cardiff. Was this a sign of successful things to come from United? Will Mata solve United's problems?
Which of these was the best signing of Deadline Day?
Kallstrom to Arsenal
Zouma to Chelsea
Ince to Crystal Palace
Zaha to Cardiff
Mitroglou to Fulham