playing Head Over Heels on my PowerBook. (I remember the game from my Commodore 64-using adolescence, though I don't recall getting that deeply into it.) (Thanks to cyflea for the link.)
Next up, it'd be good to see an updated port of Wizball (though I'm not sure whether the usual tracker-module/eurodance versions of the Martin Galway theme music would work just as well; some of the things he did with the humble SID chip may not work with the usual sample-based module.) There's already a somewhat enhanced port of Paradroid (now with added penguinhead anti-Microsoft ideology!), which is quite good.