Chatting Programs - Chat Software Clients

The programs that I use for chat and I know are tho following:

• Yahoo! Messenger - friendly look, fast file transfer, photo sharing, pretty god voice, excellent for webcam chat, nice avatars and funny smiles images. I think it has a bug because some links are not transmitted. (with or without intention :D )
• Skype - very good for voice chat, not very fast file-send but very stable and less errors.
• Msn Messenger - old and borring...
• Google Messenger - I tried to install it some months ago but I had an error and I gave up. Anyway... there are only few users for Google Messenger
• ICQ - I have never used it
• mIRC - Shareware IRC Chat client - I haven't used it for 8 years... I think it is for kids
• Trillian - chat client for several chatting services: Yahoo, MSN, ICQ, etc... I don't like the interface and the mix of the friend's lists. (you can connect with 3 users simultaneous)