A huge name, but high on this list because Liverpool sort of brought it on themselves to be fair.
The Portuguese winger impressed many during his formative years at Sporting Lisbon and, in 2003, then Reds manager Gerard Houllier spotted him in the Toulon Under-21 tournament and was determined to bring him to Anfield.
However, the then 18-year-old Ronaldo refused to budge on his salary demands which were deemed too high for Liverpool's strict wage structure.
As the Reds were weighing up signing a wonderkid but upsetting their dressing room, Manchester United played a friendly against Sporting Lisbon. Cristiano Ronaldo dazzled, and mugged off several United players who (instead of being upset) insisted Fergie sign him.
The rest is history. United accepted his demands and before Liverpool knew it he'd moved to Old Trafford. Cristiano Ronaldo excelled at United and has gone on to become one of the games greatest ever players. Liverpool signed Harry Kewell instead.