It's an interesting question. However, largest selection does not say anything about the quality of that selection. I can think of a few vendors with a large selection, but not all of it is of the quality I'm looking for.
As Ricardo points out, large ain't always good (WalMart for instance have a very large selection of cheap crap). If you give us some pointers as to what sort of things and what price range, we might be able to give you a better answer
