Personally, i love all buffy the vampire slayer series! I couldnt pick the best series as they are all so amazing! (Although tbh series 1 is the least entertaining but still brillaint!) i don't know what the person in the comment below is talking about because there are many outstanding episode in this series! And they arent just the last couple of episodes! Infact tabula rasa, smashed, and of course once more with feeling are my favourite episodes in the series! Wrecked, bargaining parts 1 and 2, gone, seeing red and grave are a close second! There is not one bad episode in this series!
Spike will make you laugh out loud as always! He is definatly the funniest (and sexiest! :P) character! Although all the main characters will make you laugh!
Buy buffy and you wont be disappointed!