'so...' at the end of sentences (which I say all the time)
'ya know' (which I say all the time)
'bologna' (which I avoid saying at all costs)
Also KK makes a good point about 'poner', although I only dislike the unconjugated form. It sounds like 'boner' when you say it with a Kansas accent. But very rarely do I ever use anything but the singular or associative form, so it doesn't matter much.