Bombjack, Donkey Kong and those types of classic arcade games. Bombjack had an official port, but the arcade translations like DK were from individuals that offered as more or less shareware. Good ports by those standards, but a shame that commercial, more polished ports weren't produced.
Deluxe Galaga for the Amiga is great, but it's still not Galaga. Still has this "homebrew" feel to it that's tough to shake.
I'll have to check out Cabal and the like between the two systems. Ikari Warriors and Commando come to mind too. Just seemed like the 8-bit versions of these games "felt" more solid.
