I've tried Mandriva, but it had BIG problems with my soundcard - and no solution. Tried openSuse, but it had some problems with my videocard - again, no solution. Tried Fedora, but some of it's GUI configurators were buggy and overtook some config files. Tried Red Flag. Those were the worst days of my life - lots of software, none is working. Amazingly terrible work! So, all modern RPM's I've tried were not good for me.
Tried Ubuntu 9.04 - liked it. Tried Debian - liked it. But I use Ubuntu now - just because they are almost equal for me and I don't want to delete my Ubuntu 10.04.
About hardware: I hate Intel for their g965 mobile express chipset and Sigmatel for their GREAT support of Linux. I found well-enough drivers for those in 10.04 only!
P.S. Tried Open Solaris (if that counts) - could not log in, it does not switch keyboard layouts on login screen.