Billy Sharp
During the 2011/12 season, Saints found themselves in a fantastic position in January to push onto promotion to the Premier League.
More support upfront from Rickie Lambert would help with this, so the club decided to splash out a fairly hefty £1.9m to take Sharp from Doncaster Rovers.
The move paid off big time though and as the striker netted 10 crucial goals in the second half of the campaign and became a fans favourite for his contribution (two strikes and celebration against Portsmouth included).
He was forced to go out on loan the following season and eventually left the club for Leeds.
Sharp has scored goals wherever he has played and recently overtook fellow former Saint Lambert as top scorer in English football this century with 220 goals.