"Shy" characters that have no problem interacting with others.
"Rude" characters that are surprisingly polite in the "right" situation.
Lots of white characters, even in a setting that should be diverse. 
On that note, a lot of straight characters (which is fine by itself but the instant romantic chemistry it leads to is way overdone).
OP characters. 
"Asshole with a heart of gold" (but guilty as well). 

I'm curious as to what y'all would like to see in a RP, though. Also curious if anyone here has taken measures in response to these things you see a lot of. For example, I see a lot of OP characters, so most of my characters are relatively weak in their settings haha. Make a lot of queer characters, too, so I don't have to deal with the romance.