Mmmmm....Soundboard
However, I saw a recent episode with a school casino, and this wheel where Homer bet on a number. I believe this outmatches the 32 D'oh sound, but then again, there's Woo-hoo's in between, so I guess 32 is still the consecutive D'oh record.
Just one thing...consider the loudest D'oh (when homer was in the WTC towers) and Why You Little (Bart Strangling, obviously) for sounds 28 and 29?