I like the Walmart Croc-off's, which cost less than nine dollars a set and are comfortable, don't absorb water and are light "as a feathah": Size 13: 10.7oz; Size 6: 6.7oz.
I find they're pretty grippy in lakes and streams, and they're thick enough that I can walk over gravel or rocks in the dark without painful surprises...not to mention the advantage of toe coverage. They dry as soon as they're shaken, and are fantastic for late-night treks to the loo, etc...
These are currently "out of season" at Walmart and will not return until last Spring, 2014. They're a standard recommendation on my Gear Lists for Scouts and are universally-loved by those who bring them along on trips. They are bulky in manly feet sizes, so I strap them to the outside of the pack. Of course, with the pack you see in my avatar there, I do have room, ha ha!