Kubuntu,SimplyMepis, and then my personal fav. wee little Damn Small Linux.
Those are my reccomendations. There is so much out there. If you want more insight go to
www.distrowatch.com.
If you want to play around with a non-linux but free os. Aside from Aros.. check out SyllableOS. Its a fork of the non-defunct Atheos. Even comes equiped with an Amiga skin/theme for your desktop.
www.syllable.org
Have fun!
