My favourites in no particular order:
Doom2 on the PC
ManicMiner on the Spectrum
Wipeout 2097 on the Amiga
Raiden II on the Arcade jamma board
Maniac Mansion on the C64
SimCity 2000 on the Macintosh 68k
Wipeout 2097 was ported to warpos later,i dont consider this an 100% amiga game,it is something different.Also the simcity 2000 was faster on amiga running shapeshifter 68k mac emulator than on the native amiga,(and mac too!) that's the crazy stuff,an amiga port of the same game was slow and the emulated one was good...