How about 'Narf! Poit! Troz! Zort!' ?
I use 'Uh?' and 'Bah!' in some of my posts. No, I don't say 'eh', that's ENGLISH Canadians who say that.
I also like is to invent acronyms, but the problem is that I always find that my acronym has already been created before when I look it up on Google.