Well I am going to cheat and include PSN for older games so here goes...
1. MK9 (just a huge MK fan and this is their best game so obvious choice here)
2. MvC2 (amazing gameplay, very fun, other than infinites haha not too much BS)
3. UMK3 (from MKAK, also played it in the earlier days, great cast, smooth gameplay etc)
4. UMvC3 (despite the x-factor BS, Wesker & Zero etc, still love the game, like to use my imagination with team synergy etc)
5. MKA (not many people like it but I quite enjoyed it. deffo not tourney worthy but loved the cast)
Most of the other games that usually would make this list will not since I played them on other consoles (PS2, SEGA etc.)
Also SF x T sucks ass.