Virgin Islands. I wonder how that would work, though.

Guam is a U.S. territory but they have their own government.

It wouldn't.

Hopefully Puerto Rico. I want me a latin lover.

There are so many actual options
http://en.wikipedia.org/wiki/51st_state

Puerto Rico, Washington DC, New York City, Guam, Virgin Islands, American Samoa, Northern Mariana Islands, California splitting in two, Texas splitting up to five times, and Superior.