Can somebody suggest a good free tool for analyzing .Net memory dumps other than Adplus/windbg/sos ?
I fully recommend .Net Memory Profiler. Beside being a great live memory profiler for .Net applications, it can also load memory dumps, and let you traverse the objects in the dump in a very intuitive an easy way.
Opening big dump (> 1 GB) can take a few hours though, but for us it's worth the wait. I don't know if they have trial version, but if they do you should definitely give them a shot.