I gotta tell ya, I’ve been making good strides with Linux Mint. So far I’ve been able to do quite a bit with it and get several Windows apps running including the Steam client. Never thought I’d see that happen. 
In addition I found a way to convert Theora-formatted videos over to AVI suitable for YouTube upload, oddly enough with a Windows app inside Mint. Hey, whatever works, right?
I’m going to bring out the “big guns” so-to-speak and try to run Half-Life 2 in Mint. As more or less all gamers know, HL2 is a very demanding game resource-wise and an excellent test of this particular Linux distro’s abilities as an OS you can play games on.
In this video you will see how I was able to get Steam and HL2 in the OS. With Wine-Doors it’s just as easy as Windows. No joke.
To note: I seriously doubt HL2’s performance will be as good as on a Windows XP box. This is not to say Linux doesn’t have the performance of Windows, but the game wasn’t designed to run this way. But heck, even if I can get it running I’ll be a really happy camper. 
Rich,
What version of Linux Mint do you have? I’m running Darnya (4.0), and Wine-Doors wasn’t installed by default. I had to grab it from the software portal. I tried installing some apps with it, and they all appeared to install smoothly until the end, where Wine-Doors froze. I tried running Steam and I couldn’t see any text. I suspect this is because the windows fonts installation also failed.
It’s Linux Mint Daryna 4.0. After you put in Wine-Doors make sure to add the Microsoft specific stuff like the MSI installer, VB runtime libraries, DCOM and so on. Whatever fails in Wine-Doors can be be attempted to be installed again without issue.