The 1987 MSX2 version of the classic coin-op, Ikari Warriors, is arguably the best 8-bit conversion of this scrolling shooter around. It was converted by SNK themselves, so is about as authentic as an MSX fan could hope for. In fact: the producer of this port was Koji Obada, who designed the original arcade game.
The scrolling is smooth but slow and the game lacks the cool music of the C64 version (it does have music, but it’s bleepy crap), but it does have the simultaneous two-player mode of the arcade original, which is good.
Of course this conversion does have a few drawbacks, like sprite tearing and some slowdown – especially in two-play mode – but overall it’s an excellent port, well worth a play today.