Personally, Id say go for either a Gnome based one (I like Debian GNU/Linux myself, Squeeze is an excellent release. It requires a little bit more tweaking to get it to Ubuntu's out of the box feel, but it'll be overall a lot faster (at least it feels that way, probably 'cause of less cruft on initial setup) and 'prettier'.
Once you get plymouth (the boot splash) working with the space fun theme, you get to watch a little space ship move across the screen as it loads, but it loads really fast anyhow, then you install compiz and configure that, and it's all smooth sailing.
Turn on spatial nautilus for a bit more of the amiga feel (at least I always thought it felt more 'amiga'.
Currently I'm running Arch Linux using Gnome 3. I found a Steam Punk theme, and it's positively awesome!
http://samriggs.deviantart.com/art/Gnome-Shell-Old-Steampunk-251805897Check it out!
slaapliedje
