The Graham Norton Show is hilarious. Graham is a comic genius! However, the show uses very strong adult humor which may not be approiate for some audiences. There is a lot of bad language and mention of sex, but in my opinion that is what makes it so funny. The show is probably fine for teenagers but not for kids.
Fun! Entertaining! Guests ranging from bad to wonderful, depends on which episode you watch.
It's insane how much more fun UK talk shows are than American ones. The Graham Norton show is particularly hilarious and fun. I would've been fine with this when I was 12 or 13, though perhaps enjoyment of it increases a bit as one makes one's way through the teen years (because less adult references will go right over one's head). Graham is an excellent host; he's effusive, fun, charming, etc. Some find him annoying, though, and the adult humor is definitely too much for children and conservative parents.