I went through every one of the US roms in a (supposedly) complete Turbo Grafx 16 rom collection and picked out the following 34 games which I keep on an SMC at all times:
Aero Blasters - Side Scrolling Shooter
Alien Crush - Pinball (awesome)
New Adventure Island - Platformer
Air Zonk - Side Scrolling Shooter
Burning Angles (J) - Top Scrolling Shooter
Blazing Lazers - Top Scrolling Shooter
Bomberman 93 - Arcade
Bonk's adventure - Great Platformer
Bonk 3: Bonk's big adventure - Even better platformer
(Bonk's revenge doesn't seem to work)
Boxy Boy - Puzzle
Bloody Wolf - Side scrolling action (think double dragon)
Cadash - Platformer/RPG (reminds me of Castlevania)
Columns (J) - Puzzle
Cratermaze - Arcade
Devil's Crush - Pinball (the best!)
Dead Moon - Side Scrolling Shooter
Dragon's Curse - Platformer
Final Blaster (J) - Top Scrolling Shooter
Galaga 90 - It's GALAGA, only more so!
Klax - Puzzle (very fun)
Legendary Axe 2 - Platformer (if you like long-haired men in loincloths, you'll love this game)
Legend of Hero Tonma
Neutopia - Zelda-ish Adventure
Neutopia 2 - Adventure
Ninja Gaidan (J) - Platformer
Ninja Spirit - Platformer (you can't go wrong with ninjas!)
Parasol Stars - Arcade (Bubble Bobble 3)
R-Type - Side Scrolling Shooter
Sidearms - Side Scrolling Shooter
Soldier Blade - Top Scrolling Shooter
Splatterhouse - Platformer (Revered in it's day as the most gory game ever made)
Super Star Soldiers - Top Scrolling Shooter
Time Cruise - Pinball
Zipped, they only take up about 8 meg total. When I get some time, I plan to go through all of the Japanese games to add to my "portable stash". Keep in mind that these are games that
I like, and tastes vary. For instance, there's not a single sports game that made the cut