nprof
nprof is designed to be not only a fully-fledged profiler for .NET applications, but also a complete API that can be used to build other profiler front-ends, as well as extend the default GUI with new visualization tools.

NProfiler
NProfiler is an application profiler for .NET that is capable of gathering performance metrics about a managed (.NET native) application and allows you to analyse this data in order to identify performance problems in your applications.

Prof-It
Prof-It is an easy-to-use standalone profiler for C# that measures execution frequencies for each statement while keeping the instrumentation of the source code to a minimum. An optimized strategy for finding basic blocks, incrementing their counters and calculating counters from others makes Prof-It faster than every other profiler, that can collect execution frequencies for each line of code!