[spiroyster]

I used to have a neogeo back in the day. Great console, the only 16-bit system which came anywhere near replicating the true arcade feel in the home Given the prices they started fetching (even in the early 2000's, and especially MVS stuff) I regretted selling it... but then again emulators back in the late 90's (neoragex on K6-233) could run the roms fast as a neogeo could. And I'm more a software guy personally, not so bothered about hardware.

For classic neogeo-ism, it would have to be MetalSlug or Samurai Showdown imo. There were some other great games though... ones I used to play a lot and would recommend:

Platformers:
Metal Slug 1 or 2 (X is just 2 with new artwork, X and later were past neogeo's hayday).
Top Hunter
Eight Man
Shock Troppers

Beat-em-ups (neogeo's trademark genre!):
Samurai Showdown
Fatal Fury
Waku Waku 7
King of Fighters
King of the Monsters 2

Sports games:
Baseball Stars 2
Super Baseball 2020
Street Hoop
Neo Turf Masters
Super Dodgeball
Neo Driftout

Puzzle:
Neo Bomberman
Money Idol Exchange (highly rated)
Puzzle Bobble

I wasn't so much a fan of 'bullet-hell' games, but shmup's were also a neogeo trademark genre so maybe look a some of those.