It's a shame that some publishers (ahem, Maxis [1]) won't allow their 20+ year old software to be hosted on the site. Macintosh Garden would be a great place to preserve and archive these old games.
Still a great site. A few months back I downloaded some handy utilities from it while down the nostalgia rabbit hole. [1]
After setting up Sheep Shaver (seems to be the best ppc emulator capable of running MacOS 9), I dusted off my old copies of Marathon 2 and Myth. It was rather enjoyable, running all that stuff on my 2012 MacBook Pro.
Somewhere I saw a 68k emulator that ran MacOS in the browser. It would be super cool if these guys linked that into their site so that every piece of software was running within the browser... :D
I really like Nanosaur II and it still runs on OS X (at least it did in 2014). I installed it on my 2013 Macbook Air and it caused the fan to come on full blast.
[1] http://macintoshgarden.org/author/maxis