The closest thing to "perfect" SNK did was KOF '98. Huge character roster with lots of depth for each character, surprisingly balanced, especially in team mode where you could put a couple "cheap" characters on your team to balance things out.
SS4 was broken, and favored turtles and abusing stupidly easy patterns (Tam Tam standing A, Galford's no-lag everything, Amakusa's unlimited ability to turtle, etc.).
Real Bout 2 was slow, boring and shallow.
MOTW is up there and you could argue it was close to "perfect," because it had a lot of what fighting game fans at the time wanted (including a surprisingly good story, which no one expected from a fighting game), but it also had a pretty small character roster and some dumb, dumb, dumb fake taunt infinites. Dumb. But still easily one of the best fighters on the Neo, and not just because it looked pretty.
SS2 was broken as all hell, but is still great fun and one of the best, most recommendable fighters on the Neo.
Both Last Blades were too shallow (and the games were too similar to each other). If you're not a fan of Japanese cartoons that take themselves too seriously, or of weepy-eyed "emo kids," you also probably won't care for the character design.
No Neo fighting game was perfect. '98 was the closest.
