It is said of a person who is either very funny, very entertaining, or both. It is also said of a person who performs some outstanding act or favor. It is a compliment, usually. "That joke was great! You're just too much!"

It can be said when someone has done something incredibly good for you, maybe even too good. "Wow Nozturk, I know it's my birthday, but four dozen roses?? You are too much!" But it can also be said in a number of other circumstances; someone is being overly funny, someone is being sarcastic, someone is being difficult to please, the list is somewhat endless. Because it is a spoken statement that follows some interaction, the person that you are saying it to (and about) should know why you are saying it. Quite often, it is said to end a back and forth conversation, such as: I think that poodles are the best dogs to own. I do not agree. Why do you say that? Well they are too hairy. Oh, there are plenty of dogs with far more hair than poodles. Then they are too ugly. Ugly, why do you say that? OK, if not ugly, they are mean. I have known dozens of poodles and none are mean. OK if they are not mean, they are too clingy! You know, sometimes you are too much! Yep, I know!.

We can’t talk here. There’s too much noise.