Question: In Java is this nice tool called [FindBugs](http://findbugs.sourceforge.net/).
Is there something similar in .Net?

Answer: 
Here is [Wikipedia List](http://en.wikipedia.org/wiki/List_of_tools_for_static_code_analysis#.NET) and [CodeRush](http://www.devexpress.com/Products/CodeRush/) is a nice tool to use for .NET.
Try [PVS-Studio](http://www.viva64.com/en/pvs-studio/) is really great, can find a lot of obscure bugs. The drawback is it is commercial product and can be expensive.