hedwards: I tend to recommend Linux Mint Cinnamon for desktops as it's an easy distro to learn to use and it has a comprehensive repository for most software you'd want.
I definitely recommend getting crossover for Windows software, the individual bottles for each piece of software is quite nice. Also, there's an automated system for downloading and installing a lot of software.
If you're not sure, I'd recommend downloading the Linux Mint DVD and try it from there, you get a more or less complete install to play with before you actually install it on your disc. It's a nice way of trying things out before you commit.
JudasIscariot: I am waiting for us to release the penguin! *ahem* I mean roll out Linux support before I start rolling in any way, shape, or form as far as Linux gaming is concerned :) I want to compare the Linux versions of our games against their Windows versions and see what runs better :)
hedwards: I think most of the DOSBox games should be a good bet, but I can hardly wait to hear more information about newer games that have Linux support elsewhere. I don't want to commit on my Wasteland 2 keys until I know that I can get a Linux copy here.
Obviously, it's still too early for anybody at GOG to officially announce that one way or another as the game is still in Beta.