Tekken Tag Tournament 2

Based on the search results, King of Fighters 2002 UM appears to be the game matching your description, featuring approximately 60 characters and serving as a compendium of the franchise's roster.

However, if you're referring to a more recent title, King of Fighters '98 UMFE (Ultimate Match Final Edition) is described as a remake that "tops every game in the franchise" with 62 characters, essentially compiling every King of Fighters character into one game.

Both games exemplify the character-rich approach you're describing—combining classic fighters from across the series' history with a roster that represents the franchise's most comprehensive character selection to date. The emphasis on legacy characters alongside newer additions makes these titles stand out as the most character-dense entries in the King of Fighters series.