You forgot bubblers!

Bubblers
Pros: Smaller than a bong. Water makes for a smoother hit. There's always something enjoyable in the mere tactile sensation of hitting a pipe (as opposed to a joint). Don't waste much weed. Often very pretty.

Cons: harder to conceal than a pipe. Don't allow for huge bong rips. For some models, not spilling the water can be difficult.

Overall, my fave piece is a really large glass on glass bong, but that aside, I love my bubbler!!