Sheldon’s shtick has gotten old.
Leonard was never funny. Ever.
Howard was genuinely funny and the second best character after Sheldon. He was great at being the creepy guy who would hit on anything that moves as long as it belonged to the other sex and was not his mom. Getting married was the worse thing that could have happened to his character.
Raj has become incredibly annoying. Annoying enough to make you want to stop watching the show. Which is something we should all be doing by now.
Penny is like those women in video games. Her sole purpose is to be the eye-candy. She brings no other value to the show.
Bernadette is occasionally amusing, mostly when she’s imitating Howard’s mom. Otherwise she’s annoying. Very annoying.
Amy is interesting but like Sheldon it’s only a matter of time before even her character gets boring.
Priya ties with her brother to become the most annoying character on the show. In fact the entire Koothrappali family is the epitome of annoyance.
Currently the only funny characters on the show are Howard’s mom and Stuart, the comic book store guy.