I am a newer brewer and I am concentrating on some variety but centered around a theme. I like crisp beers with some floral character. I went straight for a keg system too so I am really concentrating on refreshing, session beers. So I am thinking of rotating among pilsner, kolsch, american wheat, APA, witbier, maybe a belgian blond. I also like the seasonal aspect advocated by maynard above. These styles in my theme also allow me to follow seasonal temperature changes in my basement/fermentation cave.
So just as everybody says variety, I imagine they gravitate to their favorite styles. But if try and figure out what makes those beers similar, then within different recipes you will learn how you are accomplishing your preferred beers.