I love soi-disant. It rolls off the tongue much more trippingly than "self-appointed" and the literal translation from the French is much more to the point and scathing.

I used it in a meeting at work some time ago, and found everyone looking at me with blank stares. I said "sorry, I meant self-appointed" and moved on. After the meeting one of the (supposedly all university-educated) others at the meeting came up to me and asked me how "that Maori word" was spelled ...