For a long time now FxCop 1.36 has been in Beta. I thought that maybe the standalone tool had been dropped or something but alas I am wrong, and thankful for it.
StyleCop, formerly C# Code Analysis (? I seem to remember the version prior to this was called that, may be wrong) fixes a tonne of bugs. The previous version broke several things in Visual Studio like the properties window for a project, this is no longer the case. There are a few rules that I don’t really like. One no more so than the naming of member variables, I believe it will give you abuse if you use a pattern like m_myVar, or _myVar – the tool by default will tell you it should be myVar. This is a very subjective rule though. I tend to just customize the rules for a few things and go from there. Still only works for C# code.