Several people I know swear by the Olympus XA, and it's one of the smallest ones out there. All of the Olympus Stylus series ones are great imo, but some are more expensive than others. I have the Olympus Stylus Zoom 140 which seems to be pretty cheap and reliable. A friend of mine has the Olympus Infinity Stylus that we both love.
Honorable mentions: Pentax Espio 140V and the Fuji DL-150