I'm surprised you have never heard of Crocs, perhaps you've seen them but never knew their name.
www.crocs.comThe rip-off version would be, well rip-offs of Crocs made in china or other 3rd world countries.
I personally think they are HIDEOUS, but 80% or so of my teammates all wear them, in one version or another. Our steers once said to me that its quite well in terms of grip on the wet deck.
This one is supposed to be superior in variety of slippery surfaces
http://www.crocs.com/crocs-bistro/10075,default,pd.htmlHope that helps, good luck!