That was the first one to pop into my head as well.

For Angel, it was "Somehow, I just can't seem to care."

For Buffy, there are so many moments, but because I found the series in the third season, I knew much of the story before I saw the moments, so my HSQ was low. I imagine, if I'd watched from the beginning, the moments would be times like Angel vamping out while kissing Buffy for the first time, Angel turning into Angelus, and Buffy killing Angel. A subtle HSQ moment, and the first I experienced in real time was Faith showing up at the Mayor's office. I knew she was lost, but I didn't know she was planning to get even more lost and with intention.

As for Angel, what P-C said--that "And yet, I just can't seem to care," from Reunion, when Angel locked all the lawyers in the wine cellar made me catch my breath. To be fair, Angel holding the pillow to Wesley's face had about the same impact on me.

You know, having only started watching in Season 5, so no Angel falling from the sky, I have to say the end of OMWF, when Buffy and Spike kiss. My friends and I practically fell off the sofa watching that we were so surprised.

Also thinking of that made me realize, again, what a moron I was for not realizing Buffy would be the one to die in The Gift. I was so sure it would be Xander or Spike or Giles. The end of OMWF practically is the end of the gift, except that Spike succeeded in saving Buffy from sacrificing herself for her sister.

Buffy killing Angel. No doubt. I didn't have the internet at that point, so I wasn't spoiled like I tended to be later on. That was what changed it from 'this is a very good show which I enjoy' to 'holy fucking crap, how can tv do this to me?!'

Also, Tara dying. I'd heard it was going to happen, but not when or how. Owch.

Buffy killing Aangel.

Darla staking herself.

Too many others to mention.

In Angel, I think it was Darla standing up at the bar and being pregnant, yet still a vampire.

I think it was Darla standing up at the bar and being pregnant, yet still a vampire.

Darla staking herself.

I almost put this, but then I thought I might have been spoiled for it. Then I couldn't remember. Of course, spoilers don't eliminate the HSQ, they just give it in a different form.

Buffy killing Angel.

This for me too. I had the same reaction as Jars.

For Angel, I think it was Justine in the closet.

Angel turning evil-- not that unexpected (not that I expected it, but it was in line with the asshole who takes your virginity trope). But Buffy killing him despite him having a soul-- that fucking slayed me (pun unintended) like nothing else before or since. And kudos to DB for selling the distinction between Angelus and Angel in those moments.

Angel would probably be Dru re-vamping Darla.

It's a toss-up for me between Buffy killing Angel (totally unspoiled) and Spike and Buffy kissing.

I haven't watched enough of Angel to say for sure, but locking the lawyers is my top one from that show at the moment.