All the Angel/Angelus moments are excellent! I love it when he is bad, but I also love it when he & Buffy are together like their date at the ice-rink! And of course the moment of perfect happiness! Also, when he gives her the ring! When she kills him it is so sad too.
Jenny Calendar's death was also done really well & the part where Angelus is watching outside the house when they hear the news. I really liked the fact that he was completely obsessed with Buffy even without a soul!