This is a toughy. I said Angel, just slightly better. I wonder if there's a bit of a gender split or age factor involved here?
Do more females prefer Buffy? Seems like it. I'm a guy, if there was some doubt, lol.
There are too many factors to consider...I thought Angel was bland and less interesting visually, thematically"”at first. But it grew tremendously during its run. Buffy was always a better looking show, better art direction. Angel was more adventurous, innovative with the fight choreogrphy. Angel was more expansive in its settings, scope"”more spread out.
I loved Buffy, but I thought it kind of outgrew its setting by the end of season five. It got more pointless and claustrophobic for all the Scoobs to be stuck there in Sunnydale. By 7, it was ridiculously cramped, all cooped up there in Buffy's house.
Angel got more expansive as it moved along. Going from Angel's little crap office to the Hyperion and Pylea to WR&H. Roaming around LA. And it seemed like more flashbacks to Europe, not sure...
I dunno, just enjoyed the themes in Angel a bit more, though I love Buffy and her Scoobs. Buffy obviously has a much, much, much larger impact on the culture...