What do you use Linux for that is of utmost importance to your every day life?

I used to do really stuffed shirt business-critical stuff, but I find it quite a shock to see how much consumer-grade work Linux can also do. You know the obvious stuff... converting video, playing music, streaming, using a scanner, managing your finances...

I've got a laptop here that I haven't booted into Windows 7 since after it arrived on my doorstep and I shoehorned in Fedora 12 a few weeks ago.

Other than games (*ahem* BORDERLANDS!!!), I am at a loss for what I can do in Windows that I can't do in Linux. Of course I'd like a better replacement for the Agent newsreader in Windows than Pan, but Pan will do when everything else is working out as well as it is.

So... what missions critical do you have for Linux, and how does Linux stack up?

It's funny to me that there still seems to be a whole class of Linux users that only know it as a server OS and are surprised that it can handle ordinary desktop duties.

My missions critical are writing, keeping up with the news, and watching TV shows my DVR craps all over.

True. All I did with it at work was use Linux for server and thin client operations.

I need to get a USB or firewire videocap thing to test out MythTV and get about turning my desktop into a DVR. What devices would you suggest?

I haven't done MythTV, so I can't advise you on it or anything similar. I just use the Network TV websites to view episodes of shows I miss from time to time.