Fedora and Slax.
ubuntu. i have it dual booted with windows 7 at the moment. although ubuntu is the default os. it just works, i know that may not be the case for everyone , but for me it is fast, has everything i need and works.. and the thing i like about linux is i can customize it easily and make it really unique, because i like being an individual
My Favorite Linux is Backtrack & Blackbuntu
I've only used unbuntu... I am not a big linux fan but it was fun to use for the time.
Ubuntu is the only linux OS i can give my word on. Their's way to many other Operating systems i can't rly vouch for.
Ubuntu is really nice, on desktop or laptop, Ubuntu has the best support for wireless cards on laptops, but i think Mandriva is better on desktop.
Right now it would be Ubuntu... when they don't do things like Unity.
Also, keep an eye on Mint.
SuSE FTW! Been a LONG-time favourite of mine. Probably since 1998. I try new distros (or new releases of distros) every so often, but always seem to stick to SuSE for my own, primary system. It just seems to combine the best of all worlds for me: Massive core package library; more sysadmin focused than user-focused; but user-friendly too. :-)
mine is Ubuntu 10.04 and Linux Mint 10.04. I've tried newer versions but had problems getting some of my programs to run on versions 11 and newer. The install was complicated and I'm not very tech savvy to understand what was needed. But I love how these two versions work on my laptop and the speed. so much faster than windows.
Ubuntu Gets my Vote...