centericq
Every so often you come across a piece of software that just seems right straight away. I've been using Gaim for my ICQing, and never been really happy with it. It seems to be too sensitive to network issues, popping up the reconnect dialog way too often. And generally it seems lacking in some way. So I was very please to discover Centericq recently, a text based chat client that supports all the usual protocols. Installed the FreeBSD port and had it configured and running in less than a minute. Very clean, unfussy layout.
A couple of things I need to either get used to or figure ways around though, I'm used to pressing return to send the message, Centericq uses ^X which isn't that intuitive. And being text based it isn't obvious that someone has called you when you're running it in a window on an other desktop, or hidden behind what you're doing. Maybe I can get it to beep?
Running it on my FreeBSD server it complements Pine very well as a text based tool. Maybe I'll even be converted to lynx soon.