DAPHNE Arcade Laserdisc emulator
You can have your Windows games running under Crossover, I'm happy playing Dragon's Lair. Those of you of a certain age will appreciate what I am talking about, for you youngsters out therecheck out this Wikipedia entry for a taste of what awaits you. Thanks to DAPHNE you can finally play all those cool games that were available on Laserdisc (think LP sized CD's, for those of you who have never seen one), and yes there were cool games available on LaserDisc.
This open source Universal Binary is free, so find yourself some ROMs and enjoy the trip down memory lane. Now if only I could find a way to get my Mac and my Vectrex talking to one another.