Drow. It is possible to play one that isn't a Drizz't clone, or a dominatrix bikini babe, or an aloof sadistic biatch, but so often people don't look beyond the stereotypes. Then if you do have someone playing a female drow of the non-evil variety, other players are likely to tell her how she should be disdainful to men, and order them around, because that's what female drow do. Nevermind that if she enjoyed that kind of thing, she'd still be hanging with her sister priestesses in the Underdark, and not out trying to right wrongs as an adventurer.
Ha! I almost forgot about this one! This trope is so very worn out.
I especially love (and by love, I mean white hot burning hate) how hung up players are on the concept. In my campaign world,
there are no drow (at least, not as they are presented in the books). Dark Elves exist, and they do live underground for the most part, but they have nothing to do with spiders, Lolth (doesn't exist), are not inherently evil, etc. Yet players still want to play them "by the book."
I get really tired of explaining over and over again how this is not campaign appropriate. Why are people so fixated on these tired tropes? I got over this when I was 15, along with most gamers I know, but I've gamed with 30-somethings that were still hung up on it.
The Lone Stranger, aka Mr. Dark and Mysterious, aka the "I'm antisocial and uncommunicative and expect these strangers to welcome me into their party even though their characters don't know me from Adam". We had one of these try to join mid-game in a Temple of Elemental Evil run. He would not talk to us because of some vow of silence. He didn't yet have telepathy, although he was working on it IIRC, and didnt so much as write a note when we demanded that he tell us who he was. So we fought and drove him off. Worst introduction of a new PC to the group ever.
I don't mind as much a mildly anti-social character, or the occasional brooder, as long as the player remembers that they are playing a social storytelling game, and adjust accordingly. My players are all okay with this, and still find ways to integrate their social outcasts into the group. See also not being a 15-year-old "emo-kid" anymore.
Orphaned characters who are the lost heir to the throne, the Chosen One, the Dragon Reborn, or the destined wielder of the Ubersword Reforged. It is a great fantasy trope in a novel. In RPG play it tends to wind up either being dropped as a plot hook so you can focus on the rest of the adventure plot, or else makes that character the center of the story, with the rest of the party relegated to support staff. Been there, done that, got the t-shirt.
This is another one I don't mind, so long as the DM and other players are all on-board with this. Usually this means making sure everyone has a destiny or significant role to play in the prophecy or whatever (i.e. not just The Dragon Reborn, but the rest of the ta'veren as well). That said, I like it once in a while, and preferably as dictated by the campaign. Not in
every campaign.
It can be such a DM-nightmare, and what happens if that character dies? It can really break the narrative. If that happens, you can either pack it in, find a way to write around it, or "fix things" - though doing that will destroy any sense of danger the players may have been feeling, and may well be worse than the other two options.
What's really annoying is when you go ahead and drop a plot hook like this on a character, and the player goes out of his way to screw over your campaign idea. My wife had this happen once; player was given a plot-forwarding macguffin, then, realizing this, knowingly triggers a trap that got him imprisoned (like the 2e spell). Now, 6-odd (IRL) years later, we're finally getting to un-do the damage.
