have a read of: http://distrowatch.com/dwres.php?resource=major

personally i like the distros on a short release cycle (6 months), because you get new stuff quickly.

i get a bit grumpy with fedora, because i have had a few issues where they say its not a bug but a configuration issue, in similar place ubuntu will aim to set a better default. i don't mind modifying boot options, or config files, but most people prefer not too. but for any 2 distros you will always find someone whos laptop works better with one, and someone else for whom the other distro works better.

most distros have a live CD so you can have a play with out installing.