I had a dual boot, too. At the first time, it was just to test but it was perfect for the kind of work I do, so I keep it.I think everyone should test it because it's addictive
What about Debian?I've used an old stable version on a pentium II ( ) to create my own local DHCP/gateway/samba filesharing/ftp server.I use another stable version on an 2002 laptop too, everything is ok, too. But as xboxrulz said, if the distribution is used on a "new" computer, all the large distributions works fine.