IMHO you can't go wrong with a good dice set. In all seriousness this is like asking what's the best car to buy with no more information.
What are you looking for? Do you want a set of customs or will someone's premade concept work for you? Are you partial to clay/close to it (i.e. China Clay) or do you like the silky sheen of ceramics with their edge to edge artwork? How much are you looking to spend? Is security at all important to you? How about uniqueness?