I'm finding that the controls file in my MAME isn't always correct on 4-way vs. 8-way... :\
Off the top of my head, I *know* these are 8-way:
1942
1943
Galaga 3
Gyruss
Juno First
Scramble
Super Cobra
Time Pilot
Xevious
Zaxxon (pretty sure)
Off the top of my head, I *know* these are 4-way:
Amidar
Burger Time
Crush Roller
Dig Dug
Dig Dug 2
Donkey Kong
Donkey Kong 3
Donkey Kong Junior
Frogger
Jr Pacman
Ladybug
Mr Do's Castle
Mr. Do
Ms Pacman
New Rally X
Pac Man
Pacman Plus
Pengo
Qix
Space Panic
Super Pacman
Off the top of my head, I *know* these are 2-way (some use sticks, some use buttons):
Galaga
Galaxian
Mappy
Moon Cresta
Phoenix
Space Invaders
Off the top of my head, I *know* these are spinner (can be used w/ trackball too):
Arkanoid
Off the top of my head, I *know* these are trackball:
Centipede
Millipede
The rest? Not sure.
-Jason