Don't get either, get S5, although no Angel, it's the best Buffy arc ever. S5 has drama heartache tears (Riley leaving, Joyce dieing, Buffy dieing) and your funnnies (Olaf The Troll God, Buffy bot)). But that's just my peronsal opinion. If you just want to choose between S3 or S2, I'd say go with 3, it's the essence of Buffy The High School years, S2 is just too corny at moments ("Bad Eggs")