I'd say that the most compatible Amiga is an A1200 with a Blizzard 1230 with some extra ram, and WHDLoad installed.
There's an awful lot of games you won't be able to play on a vanilla 500/1200 or whatever.
A cool thing about having an accelerator is that the WHDLoad patchers often tweak the games so they will take advantage of more powerful machines, giving the games a new lease of life. Or in the case of games like Red Baron which in my view was just too slow to be playable in the first place, they have actually brought it to life.
