When it comes to profiling and performance tuning of application for .Net application, the proprietary solution can be quite expensive. However, I stumble upon SlimTune recently. It's a free .Net profiler and I find it quite sufficient for common profiling needs.
If you just interested to see your application performance hotspot, it already does that quite well. It's not fancy, sure, and the GUI need getting used to initially, but it does it's job fine. I can spot and tune the performance issue quickly with it.