I hate facebook chat with a passion, its crap, buggy, and just plain annoying. Facebook and IM conversations should NEVER mingle.
I hate the n-europe PM system too, its so slow and cumbersome >_> (forum PM systems in general, not JUST n-europe) although I use it when neccesary.
I use msn because its easy.. I don't hold massively long conversations with most people and i can be lazy in replying sometimes... If your friends get offended because you don't reply in 5 seconds well they aren't worth being a friend, and need to cheeeeel. :P
One thing I hate about MSN. I have one contact, a fella I do like talking to on occasion... but he's never done making multi chats. With all his belfast mates, who I don't know or care about =P Then he has the cheek to moan when I leave...