Profiling .Net code

[Michael Schall]

We are running into some performance issues in our applications using iBatis.  Looking at a log4net rolling file, times from start to finish of select statements can vary from 15ms to 400+ms for the same call with a sql trace saying that the sp has 0 duration.  I am looking for a profiling tool that can help us pin point where this time is being spent.  I have downloaded nprof, but it is not the easiest to use, and there are no docs helping me out. 

What are people out there using for a profiling tool?  What have you tried and liked / not liked?

Thanks.
Mike