Márcio Amoroso – £22.95m
Márcio Amoroso arrived in the Bundesliga as their most expensive signing ever and remains in the top five 18 years later.
Borussia Dortmund signed the Brazilian to score the goals they needed for a title challenge, and he did just that.
His first year saw him score 26 goals in 46 games in total, helping his side to the Bundesliga title and second place in the UEFA Cup.
He only managed 17 goals in another two years as injuries limited his appearances but that first year fully justified his price tag.