I can vouch for BF2, oblivion, and MW2. You won't have any problems with those games on your setup at a pretty decent setting. By BF2 you mean the actual BF2 and not Bad Company 2 correct? Either way BC2 would still run reasonably well.
Your system is pretty decent, especially for some of the older games on your list. Your machine also has a lot of potential. All you really need to do is upgrade your video card if you want to run the latest games. A GTX550Ti should be able to at least run those on low-medium.