Alfredo Di Stéfano is the most obvious candidate for the “best big money transfers” category methinks, and should compulsorily be #1 in these type of lists. To fully appreciate what he meant to the institution after signing from Millonarios, you have to consider Madrid from the 1930s to early 1950s...as they were far removed from their modern perception of grandeur: hadn't won a La Liga title in 2 decades, trailed the likes of Barcelona, Athletic Club and Valencia in terms of the highest domestic honors, and progress was slow in spite of Santiago Bernabéu's best efforts as they had emerged from a period of austerity. By the time Di Stéfano left the club, Madrid had won a record 10 La Liga titles, 5 European Cup titles on the trot, and had solidified themselves as the grandest club in fútbol — establishing a heritage of glamour that would attract the talents of Cristiano, Zidane, Ronaldo, Figo, Kaká, Beckham and so forth in decades to come.
- Another obvious one is Diego Maradona from Barcelona to Napoli. Turned the unfancied club (which was deemed fundamentally inferior to traditionally great ones from Northern Italy) on its head, won them the only league titles in club history, and became an all-encompassing cultural icon. And this was at a time when the opposition had galácticos like Platini, van Basten, Matthäus, Baresi, Gullit, Baggio, Maldini, Rijkaard, Scirea, Zico, Brehme, et cetera!
- For the understated variety, Luis Suárez Miramontes from Barcelona to Internazionale. Quickly established himself as a leader and came to the fore as the latter's version of Xavi (in terms of game-defining playmaking and organisational prowess from central midfield) as they conquered a decade-long barren spell to win 2 European Cups (record for Italian clubs at the time) and 3 Serie A titles in 4 years following the move.
Worst big money transfers: Coutinho from Liverpool to Barcelona, Mendieta from Valencia to Lazio, Nielsen from Bologna to Internazionale.
