There are three free distros (Linux-versions)I recommend you can download for free.
- Ubuntu
lots of applications, good support of hardware, graphics cards, easily obtainable on magazine cds also. If you're on a low bandwidth connection, check your local pc magazine store, and buy one 
- Linux Mint
Based on Ubuntu, posh desktop (Gnome) and stunning graphical effects (if you like them), easy to use, haven't seen this one one a magazine cd yet, 700mb to download a live cd
- Mandriva
the free version comes with less than you probably want if used to Windoze, the paid version is some $50,- and sure worth the money, if you want to spend it.
Using Linux is a decision
to do without! There are a lot of things, that work the very same, and if you can rearrange your desktop life to use free web services for writing, spreadsheets, presentation, etc. you will not notice a difference. What I personally miss most is a decent text editor like notepad++ in Windoze. Bluefish might be comparable, still testing. Those who like emacs (

), will be fully served.
But many a time you will feel
travelling back in time, say 10 years?
Also you should not be afraid of the
command line.
As for gaming I don't know. I can easily do without games. See: "do without".
It's sure worth trying