So, I've got a bit of a problem.

The main character of my current WIP (first-person past tense, if anyone's wondering) started out fairly even-tempered, but has become increasingly sarcastic and even arrogant as time goes on. This is mostly a good thing, since it fits well with the rest of his personality and stops him from being too bland, but I worry that readers will get tired of him after a while.

What do you guys think? Do sarcastic main characters easily grate on your nerves, or does it depend entirely on how they're written? I'd also appreciate examples of successful/unsuccessful attempts at this if anybody has them to hand!