Cross-platform: If you long for the DOS-based games of your youth, free app ScummVM easily runs classic games like Maniac Mansion, Sam and Max and Secret of Monkey Island on any platform you can imagine, from Windows to Amiga.
We've already featured one or two ways to play classic DOS games on your modern computer, but for a specific subset of games, it doesn't get much easier than ScummVM (Script Utility for Maniac Mansion). As long as you have the data files for the original game, ScummVM makes it possible to play them on virtually any system you can imagine, short of Skynet. The engine has actually been around for awhile, but for those of you that haven't yet discovered it, we thought it was worth mentioning.
Just load up the files from any game based on Lucas Arts' point-and-click game engine (among a few others), and you're on your way. The engine has options for customising things like graphics and MIDI emulation as well, so you can really get the full experience. Hit the link to check it out, and be sure to see if your games are supported before digging them out of the basement.
ScummVM is a free download that works on Windows, Linux, Mac OS X, Jailbroken iPhones, PalmOS, Nintendo DS and PS2, to name just a few. An as-yet-unofficial Android version is also available here.