The most interesting scripts by far are the ones with the most significant rewrites and extensive deleted/censored scenes.
Hands down, the most extreme rewrites were for Never Kill a Boy on the First Date (Owen was renamed, no Angel and the whole showdown is at a bowling alley) and the version of Killed by Death with Angel pre-Angelus rushing Buffy to the hospital and an old lady monster posing as a patient who killed Buffy's grandmother instead of her cousin (note the similarity to the Plasmavore from Doctor Who's Smith & Jones!).
The pilot script is so much longer than the unaired pilot. It's got stuff like 600-year-old Heinrich Joseph Nest being the Master's name/age. So glad we were spared Buffy's diatribes about the history textbook being Eurocentric and Joss' favorite feminists that only university academia people would have ever heard of. So beyond out-of-character/touch for a teenager to talk like that. Joss' age and education was showing hard there in the most elitist, nauseating way. Keep that stuff to Sheila Rosenberg and Willow parroting her horrible mother, please. And most notable of all, Angel rides a motorcycle and stakes a vampire outside of the auditorium, which DB even mentioned filming during the 20th anniversary. Chris Boal is the name of the guy Darla stuffed in Aura's locker.
The mentions of Angel also weren't in the earlier draft of The Pack (Buffy/Willow at the Bronze and Hyena!Xander's taunts).
The funniest is the continuity error of blood on Gunn's lip from confusing Angel's blood for V8.
The WB's censoring of City of... left a huge dangling plot thread of two separate scenes (the girls in the alley and Doyle's warning about staying away from the humans he's trying to help) that were meant to lead to Angel tasting Tina's blood, ripping his hand out of his mouth and scrubbing his hands in the sink. It's one of the only deleted scenes besides the two AtS ones on the DVDs that even managed to appear in the episode's WB trailer! The City of... script still has Whistler in Doyle's place, as well as Angel being the only one to show up for Tina's funeral.
The infamous Corrupt is the other leftover of AtS' earlier, darker direction where Kate was an undercover prostitute with a drug addiction who actually propositions and feels up Angel at one point. Cordy's "Dark Avenger" commercial from the start of Hero was lifted from that script.
One of the most underrated deleted scenes was Rebecca asking Angel in Eternity about his physiology, which included Angel giving a whole explanation about vampire physiology being metaphysical, instead of scientific. It literally explains why so many things like vampire CPR (they can talk, but not breathe--lungs are shriveled next to walnut-sized hearts) and sex don't make sense scientifically.
1x07 has a ton more scenes with Joyce, including Buffy squirreling away her dinner for Angel, Joyce talking about thinking there was a mice infestation upstairs and coming home from the hospital.
Lie to Me has more dialog in the Bronze with Buffy and Angel. They discuss Angel being able to consume non-blood drinks.
The Harsh Light of Day has the much-missed dialog where Buffy admits that sleeping with Parker was all about proving to herself that she was over Angel (dismal failure).
