The ones from NirSoft are really usefull!
I have WhatIsHang and AppCrashView from them! Recommended!

Filemon is now obsolete but they replaced it with Process Monitor, a tool that gives a good detailed info on an application or program error or crash!

I use all three of them, as they all give their own kind of info and that is handy for tracing errors and such.

My best regards, Kodiak.