Why not mix it up and start saying "word to ya mutha" like Vanilla Ice.
I say "kewl" too much, probably.

God help me if I picked this up from Grey's Anatomy but I do say "seriously? Like, seriously?" a fair bit. No wait, I think I may have got it from South Park.

i'm addicted to the words, oosh, and radical.
i need help.

I, too, say 'Word' all too often. and really, when someone says they're baking a cake, it is the only appropriate response.
I also say 'shiny' a good deal, but that one doesn't make sense to anybody but other Firefly nerds