I've been getting into these again recently and have a question about the price guide. Sports cards have both Beckett and Tuff Stuff (among others), but Beckett is the one that serious collectors actually go with.

The question is, which comic guide is the serious collector guide? I'm guessing Overstreet but CVM seems pretty decent also. On the other hand I sometimes look at a site that gives a price guide (not sure whether or not I can name it) but is that site's info total junk?