I also forgot to mention one trope that I am so sick of and which now always takes me out of anything I'm watching: melon-smashing punches to the face that knock someone on their butt and make a noise that sounds like it'd kill the average person, but don't really seem to hurt them. Lots and lots of that on Firefly.
Poor Jewel Staite, looks like a dead ringer for a young Julianne Moore, and she's the one who gets shot in the first episode and threatened with rape in the last. And of course she had to play the smiling happy friendly super-innocent character that probably would have gone to Allyson Hannigan had the show started in 1997.
I bet if the show had lasted, we'd have seen smug BTVS cast cameos.
Season 1 - The Master - Okay, that guy was in Animal House so I laughed at his line deliveries, but there wasn't that much to him.
Season 2 - Drusilla/Angel - They both sucked horribly. Juliet Landau's British accent was one of the worst I've ever heard and if I'd been watching the show in 1998 and you told me that dull brooding hunk Angel was going to get his show I wouldn't have known whether to die laughing or say good riddance. Angel got slightly better when he had to kill that teacher lady, but only slightly.
Season 3 - The Mayor - He was really good, up until the awful CGI that closed the season (and I cannot stop laughing at the idea of an episode marred by the second or third-worst special effect I've ever seen was CONTROVERSIAL when it aired.)
Season 4 - Adam - Bad makeup and that actor has had like no career, go look him up. I can't even remember his name. George something. I liked season 4 and most BTVS fans think Riley was a dull character, but I was indifferent towards him.
Season 5 - Glory - Bad bad bad bad bad actress. BAD. Worse than Juliet Landau even!!
Season 6 - Warren - He had some interesting moments, but the show only partially pulled off the moral ambiguity necessary regarding Willow turning evil, so when she ripped his skin off I really didn't feel too sorry for him.
Season 7 - A bunch of evil super demons underneath the new school. Do they even count? "The first"? Does that count? I didn't hate this season but it botched several key moments (Kennedy, Buffy getting kicked out of the house, Spike's confrontation with the black principal guy was a big fail IMO.) Another bad special effect when the town was destroyed. I wonder if anything that happens in Sunnydale makes the news. Oh and Caleb. I loved him. Hilariously entertaining. That's why I liked him best.