It used to be a general recommendation for Jabberzacs to just install Pidgin and be done with it. No more. This is my official “fuck Pidgin” post. It makes for a terrible experience.
If you’re on Windows, and need a desktop client, install Gajim. Here’s a copy of the emote pack that’s Gajim-compatible. Linux users, you too.
Android people, install Conversations on your phone/tablet/fridge/watch/whatever. Yes it costs a couple of bucks, it’s worth it. If you’re totally opposed to that you can download the source, build it yourself and install it on your own phone without giving anyone a cent. Tell your mum that you did that, I bet she’ll be really impressed. Anyway, Conversations owns, it’s a great XMPP client and you will have a much better experience with that than anything else.
Mac users, you’re stuck with Adium still. Monal is about the only iOS client worth a damn though, and there have been occasional betas of an OS X port recently. Keep an eye on it.
If you’re in a category with no good option, pop up a web browser and use the Kaiwa web client and kick on with us there. It’s nice, but has a few issues although it’s pretty early in development currently. It’s pretty and it works.