What a great question. I always figured I've brewed most the styles that exist, but turns out it's only like 41 of the beers and 4 meads and ciders so that's 45 total. As much as I love dark lagers, altbier, English brown ale, and Belgian sours (LOVE them), sadly, I have never brewed those yet, at least not on purpose. This is all about to change based on this discussion. I was already planning to brew Pete's Wicked, so that one's covered. And I've actually made an English brown before, but I added smoked malt and shouldn't have. Of course, I have brewed probably a dozen different Category 23 beers. I suppose you could say Cat 23 is my "specialty"!
Now... time to go design that perfect altbier recipe!