Neo Geo by far, without any doubts. I can't be a Neo Geo collector (because of the high cost and rarity of titles in good conditions), so emulation gives me the posibility to enjoy this old but amazing system from the past, even in better conditions than back then. Some PS2 and PS4 compilations (Art Of Fighting Anthology, KOF Orochi collection, KOF'98 Ultimate Match, Windjammers, Samurai Shodown Collection, Metal Slug 3, Breakers...) and recent ACA Neo Geo games (Big Tournament Golf, World Heroes, Street Hoop, Top Hunter, In The Hunt, 1945 Plus, Pulstar...) have given me back the feel of the best 2D console games/arcades from the 90s era.