Call me crazy, but I honestly prefer the minimalist vector look and dedicated-circuit sounds of the original to any of the ports or remakes. (Vectrex had a pretty good unofficial port, though.)
AsteroidsReg92 by Mike Seifert is the best, for me. It does crash sometimes, but it was really cool, screenmode friendly too. All classic vector looking, though shapes were actually bitmaps. And, comes with the C source if some one wants to mess around.
http://aminet.net/package/game/shoot/AsteroidsReg92
