An Internet slang term that has emerged for a non-American who loves America a little too much is freeaboo. This is a somewhat derogatory snowclone of weeaboo, a term popularized online to refer to a non-Japanese (especially, a non-East Asian) person who is unhealthily obsessed with Japan or Japanese popular culture. This term seems to have displaced the earlier term wapanese, a portmanteau of "white" and "Japanese," analogous to the more offensive wigger.
The "free" in freeaboo is a play on the habit of certain American hyperpatriots to equate freedom (at least as they conceive it) to the United States itself. George W. Bush used the word frequently in speeches after 9/11, but it truly became a trope in 2003. To protest the French government's opposition to war in Iraq, Rep. Bob Ney (R-OH), chairman of the committee which had power over food service in the Congressional offices, had "French fries" renamed to "freedom fries" on the cafeteria menus.
The move invited a torrent of well-deserved ridicule across the U.S., not to mention abroad, with people jokingly saying things like "freedom kiss" (instead of a French kiss). Since then, "freedom" has been ironically and unironically to refer to American exceptionalism and a sort of reflexive (if unproductive) pride in America, like humorously referring to inches and pounds as "freedom units."
Internet wags have invented an "-aboo" for any number of identities with varying uptake. There are Koreaboos, teaboos, and ouiaboos, and more darkly, Wehraboos.