Sitcom stars who left their shows because they didn't get along with the cast

Shelley Long from CHEERS would be the best example for this. While her reason for leaving was to focus more on her burgeoning film career (she had been in hit films like Outrageous Fortune and The Money Pit) as her last chance at making it big as a movie star, it was also apparent she didn't get along with her co-stars, who were more relaxed and open to having fun whereas Shelley Long, just like Diane, was more focused on doing her job and keeping it professional and it ended up isolating her from the cast. It also didn't help that she was mad that Kelsey Grammer took a chunk of the funnier lines that were meant for Diane. When Frasier came on the show, Diane lost a lot of that snooty humor she had in the initial seasons, her arc becoming even more focused on the Sam and Diane arc. By her last season, her character was missing some episodes with how underwritten she had become.