Well, considering we're on the SY board, Genetic and Lee 2, from the Dirty and Goo reissues respectively, are both as good as anything on those albums. Another great example is Radiohead, who have a BUNCH of their best songs as b-sides, such as
Trans-Atlantic Drawl or
Polyethalene. The Breeders and The Beatles are also great examples. I've often said that you can kind of judge a band's overall awesomeness by the quality of their B-sides, because these were the songs they could afford to throw away. If they still rock, it bodes very well for the band's creativity.