I'm quite like most of the other posters.
I have 4 taps, and I like to split them up as follows:
1). American/hoppy - IPA, DIPA, APA, Amber, Am Brown
2). Lighter/session - Pilsner, Dortmunder, Helles, Witbier
3). Brown/dark or malty - Am Oatmeal Stout, Robust Porter, Vienna, Dunkel, Marzen
4). Wildcard - here's where i brew the experimental recipes or not quite so often ones, usually a big beer. currently a doppelbock.
I brew my IPA, Pilsner, Amber a few times per year, everything else listed most likely annually, and then I try to have 4-5 things on my list to brew for the year that are different from my usual cast.