I'm not quite ready to ditch Win7 (but I'd like to!) on my main computer yet, but I've been having really good luck with Ubuntu, both as the only installation on my laptop and as a VM on my workstation. I've had to work with the virtualization more and more recently due to some website testing, and I just leave it up a lot otherwise because I like seeing it over there.
I'm using Ubunto 10.04, and I love Gnome, I love apt-get installing things (SO EASY!) and I love the built-in feel that this version has with a lot of the base installs. Chat app? Built in. Standard, useful desktop stuff installed? Absolutely. And having a desktop within a desktop is especially weird - when I use the Desktop Cube effect from Compiz in the VM it almost blows my mind.
I'm using AWN as a dock, which I like a lot, but it does come with a simple problem or two - I don't know where to find icons for installed programs that I want to put in my dock. I'm told I really should try Docky, but what it'll do that AWN doesn't is a mystery. Maybe when I run up against a shortfall in AWN I'll try it.
And I'm definitely using only Ubuntu on whatever my "real" laptop becomes this fall - it'll be time to get something then (a t410s, maybe?), and Ubuntu will be the only OS on there for sure.
That's it for the geeky linux love for now.