Is it me, or is two a very good number for tv seasons?

I've been working my way through Angel on DVD the past few weeks. I've lucked out in that the nearby Hollywood Video has most every season of any show I care to see on hand (save for Roswell and Andromeda, which I must admit is a bummer). As an unintended, but not unpleasent, side affect, I've gotten my mom hooked on watching it too. She watched a few here and there with me during season one, but I think she watched the entirety of season two and we've just started on season three. I'd forgotten just how much happened during season two. It really had a lot of good stuff.