For a while I was heavily using Adium, with many extensions, theme packs, and Whatsapp. I'm now just using Messages on mac/iphone and much prefer it. Bells and whistles are only interesting for so long. Text and emails, on computer and phone beats any long feature list.

Same for music, I had customised Winamp and another one I can't remember the name of, but now I'm back to iTunes. I do need a new podcast client now that iTunes makes it difficult to know which episodes are downloaded. Any suggestions?