Tonight, completely on a nostalgia-fueled whim, I set Google after "Glider Pro," and lo and behold it's been ported to OS X...and it's free! This is probably old news, but I had no idea. The house editor is still OS 9 only, but several additional houses have been made available by the game's developer. I know what I'll be doing for the next couple of hours.
This has got me thinking: What other classic games have been ported to OS X that I'm unaware of? Anyone know of some good ones?