I was enjoying the PC version of Mass Effect, until I decided to fire it up for the second time. Blue screens, random crashes, etc. I checked the offical forum for solutions, and lots of people are having similar errors. Even the official patch didn't fix the problems. After several driver changes and possible workaround/solutions that did not work, I am giving up on it for now.
A lot of people were having issues with ME on PC. I was experiencing quite a few lockups during my 1st and 2nd play though it, but I haven't had any for quite a while now.
First thing that surprisingly made a nice improvement for me was to simply run the .exe as an administrator. The latest Forceware drivers may have made a difference too, there are still bugs that are proper to the game but no crash or lockup at least.
Even though they made some good improvements specifically for the PC version, it remains a console port with all the cons that come with it...