Comparing sports betting and luck based gambling doesn't gives a clear picture.
For sports betting I like Sportsbet.io, Fairlay.com, directbet.eu and Nitrogensports.eu.

For gambling, primedice, betking, bitvest has its place and the new bubblesbit.com which is not even listed provides options like the old icedice site, a slide dice and has great customization for betting in a simple interface.