hehe, that's the problem when using a server-based service. and that's why p2p is going to rule the net

to answer the initial question: take your pick. think they do all the same job and i am still in the process of finding out what's currently best. here is my experience so far:
- bearshare works ok (looses/changes connections steadily), but there are discussions about encrypted packets send. also it's commercial-based and not open source.
- gnotella has a better functionality than bearshare, e.g. it continues the downloads after a restart (bearshare doesn't). but it's running slow here - better don't try to share more than 10 files. although this is ok if sharing movies, there 10 files means 8 gigs

i haven't tried the others yet ...