Bubblers are great. They get the smooth, water-cooled hits of a bong, without the potential inefficiency. Studies have shown that the common belief that bongs are healthier is false (sorry, no citation on hand); they actually tend to deposit more tar than joints. Bubblers, strangely enough, were reported to be much more effective at filtering out the tar and other gunk.

Whether that's really true or not (some argue that the method used to simulate taking a hit isn't really a good representation of normal smoking patterns, and that this invalidates the findings), and whether it matters given the recent study showing that smoking pot does not increase one's risk of cancer anyway, bubblers are definitely a nice smoke. I highly recommend one, although they can be pretty expensive. The 'sherlock' style ones where the stem curves up from the water chamber are my faves.