I especially like bilingual pleonasms--expressions that feature two words with the same meaning, for example, "the fireplace is the focus of the room"--as if it could be anything else, focus meaning "fire" in Latin.
The French phrase, repondez s'il vous plait, already has a "please" in it, so one of the most common pleonasms, "please RSVP," is really pleading "please, please respond."
Other pleonasms are unavoidable if you want to be understood. Go into an American kitchen store and ask for a paella or a casserole (both words for "pan" in Catalan and French respectively) and they'll think you want the edible contents rather than the container itself.
But the worst--or maybe the best--pleonasm of all is the one I accidentally committed when I named this blog. Vermont gets its name from the French les verts monts--the green mountains. So My Green Vermont is really saying "my green green mountains," which right now, with all the rain we've had, is certainly accurate.
I thought this was hilarious until my ever-witty spouse suggested that, since we live on a hill, I rename the blog My Green Vermont Mountain.