Originally Posted by The Question
All of Joss Whedon's shows have quirky characters who make lots of jokes. Every single one of them. In abundance. Also, none of his shows are anything like NCIS.
But Buffy and, to some extent Angel, did have characters who had really annoying speak, and it was as if it were a requirement that one had to speak like that to be on the show.
When you compare later shows like Dollhouse or Firefly, sure there were quirky characters, but they didn't generally behave like the majority of characters on Buffy (eg Xander, Willow, Anya, Cordelia etc) with the exception of the likes of Topher and others who were now more in the minority than the majority. Nathan Fillion's character was more serious than on Castle. And most of the cast of Dollhouse were quite serious, even though they did make a few jokes here and there.
By the time you get to the Avengers, the characters are still humourous but such a world away from the Scoobies. The characters on NCIS are almost Scooby-like in personality sometimes, which I find to be extremely annoying and acting almost like a bunch of saps.