During a semester in London, I actually missed very little about my home culture except for my friends. There was actually a restaurant just down the block from me in South Kensington that offered authentic, spicy chili and played music piped in from a radio station in Austin, Texas. Besides, in addition to American imports, London offered a wealth of culture and cuisine that I was eager to explore!
Once I returned to Texas, I immediately began to miss the history, art, culture, and public transportation that London had offered.
Unfortunately, I've never stayed long enough in France to miss anything about Texas but my own bed, which leaves me in a position of envy regarding those of you who have lived in France long enough to actually start missing things like Tex-Mex "cuisine." I've spent the majority of my life studying the French culture and perfecting the French language from afar, yet my financial situation does not permit me to travel abroad but once every few years, and it certainly doesn't offer me the opportunity to live in and truly explore the culture I've based my career upon!
That said, if I did have a chance to live in France, I suppose the thing I'd miss most about America is Americans, or at least the ones I click with personally.