The 1st two that come to mind are RType and Z-Out. I was a big fan (RType) of the arcade game as a teenager, and I was pretty happy with the quality of the Amiga port. It wasnt perfect, but both the graphics and gameplay were pretty well recreated. As for Z-out this is a bit of an under rated gem in my opinion. Well designed levels, and gfx are quite nice, especially as you progress (lots of parallax,etc.). Very much an RType clone, but a well done one, and with enough of it's own ideas to make it good off it's own back.
