Wow.. just wow. This app is constantly improving, and has the best interface I've ever seen in a chat client. The amount of options available is amazing, and some of the features are now indispensable to me. The only problems with it are protocol-specific features (file transfer, audio/video chat, etc), but that's really not the fault of the authors. Blame the closed IM services for those, and I'm glad that the authors of Gaim have done so much already to reverse-engineer AIM and MSN. If you can live without file transfer (although it seems to work intermittently for AIM now) and AV chat, there is no better option than Adium.