Well, I'll just have to put in the final word on this.....

SNES : Great sense of awe for those who played it when it first came out. Awesome production values, music, graphics and atmosphere was unlike anything else at the time. Control is as good as a d-pad can do, and a d-pad was all we pretty much knew. Still a classic, game that makes me happuy as soon as it is botted up.
64 : VERY pretty N64 graphics, very tight control, great level design, hard mode fairly challenging. Step backs are the voice work, but life goes on I guess. I think it is also a classic, improved gameplay wise everything over the original, made not as impressive as a game overall.
SFAdventures : Blah.
SFAssault : Ruined. Walking and 'tank level' horrible. Arwing levels not that great, can generally hover in anyone spot, bounce of buildings with little damage, most mission repetitive, blow up all the shields or generators, blow up main target. Story bottoms out.
Sfox DS : Have never played! Will eventually!