In season 3, when Angel leaves, Buffy's really sad and distraught about it, but she doesn't really DO anything to make him stay, either. I mean, what is there to do, he's made up his mind that he's "doing it for her own good". He doesn't really WANT to try, and it's obvious. In season 7 - First Date - Spike says he's leaving and Buffy's like "Um, no you're not." Just her one little phrase "I'm not ready for you to not be here" -- and he stays. Spike obviously thought she was worth fighting for. AND YET PEOPLE WANT HER WITH ANGEL BECAUSE WHY?