Street Fighter II
Super Smash Bros. Melee
Ultimate Mortal Kombat 3
Tekken 3
I wanted four series. besides that:
SF2 - duh
Melee - besides the series it made take off, has basically become SF2 but for platform fighters
UMK3 - maybe the most beloved MK game now? it would be a toss-up between this, MK2 and MK9 for a spot on the rushmore I think. MK1 is more important than all three combined but has also aged terribly.
Tekken 3 - token 3D fighter
too many other games that could go on here: Virtua Fighter 1/2, SoulCalibur 1/2, X-Men: COTA/X-Men vs. Street Fighter/MvC1/2/3, Guilty Gear X/XX, Darkstalkers, Third Strike, SF4, Garou: Mark of the Wolves, The King of Fighters '98, Smash Ultimate
Born to lose, live to win!