Tried some arcade versions of Amiga games I owned (through MAME).
Toki - arcade version is quite cool, but the Amiga version has better music (IMO). Also I couldn't beat the first boss... the Amiga version was just a question of mashing the fire button and he died without a problem, but the arcade version boss has more moves. I Can't seem to dodge his jumps! I hate one-hit-kills-you games, especially when they are also of the you-have-to-repeat-a-part-of-the-level type...
Turbo Outrun - the speed of the arcade version is just insane, unplayable. Also the amiga version had better music.
Strider - arcade version is actually quite fun. No annoying sounds, smooth playability, more spots to hook onto and neat graphics. But I hate the respawning enemies, I don't see a need for that in a left-to-right platformer.
Wonderboy In Monsterland - Amiga version is way better, but the arcade version has more variation in the monsters, and the bosses have a more difficult pattern. I got my ass kicked by the jumping one on the third level, which I beat with one hand behind my back on the Amiga.
Thunderblade - less hard than the amiga version, but it is still to boring.
Final Fight - arcade version is even better than the snes version IMO.
Mortal Kombat 1 & 2- arcade version has okay graphics and sound, but the computer is very fast. I didn't see a way to set the difficulty either. PC version of MK1 and snes version of MK2 still rule IMO.
Double Dragon 2 - piece of shit. Amiga version was the best.
Vindicators - arcade version has more variation in enemies and plays a lot smoother, amiga version has better music and sounds, and the pickups are placed a little better (fx. more fuel pickups).
Silkworm - yuck! Amiga version rules in all ways!