Play classic fighters like The King of Fighters or Fatal Fury online against friends.
Because ROMs are copyrighted intellectual property, they are not hosted on mainstream sites. You will often find them on: winkawaks neo geo roms pack
In practice, virtually no one using WinKawaks in the 2000s did this. The emulation scene existed in a state of tolerated piracy—game companies rarely sued individual downloaders but routinely sent DMCA takedowns to ROM-hosting sites. Play classic fighters like The King of Fighters