Well of course, there is that popular one:
Dev-C++. Personally I don't like it too much, but it's got a simple IDE and it gets the job done.
MinGW Studio. This one is very similar to Microsofts VC6, and you might want to look at it. It's slightly harder to use, but in my opinion it is much better than Dev-C++. Also, it's not as popular as MSVC so I don't think Crystal Space has a project file for it (as with many other projects. It does work with makefiles to an extent so you could play around with that.
Of course, you shouldn't take my opinion for granted, take a look at both of them, and see which one suits you.