WinMX has loads of results but the queues are a little disappointing.
eDonkey has massive content in the area of high quality DVD rips and programs but it's amazingly slow.
Blubster has a cult of fans who love the community atmosphere but it seems to have less than 7000 ppl online. It needs a boost from V2.0
Direct Connect has more content than anything else but the minimums are bit too high for most ppl on most but not all the hubs.
FastTrack has mostly small versions of movies and try to get major software programs on it. Not much choice.
The Gnutella network has many technical weaknesses so the improvements in the various proggies are neutralized to some extent.
I'm not complaining though cuz I appreciate all these programs and what they do for everyone (except the content owners):however none is perfect.