what car is "best"? Toyota camry vs Toyota corolla vs Honda accord?

I seriously barely know anything about cars? This will be my first car (15 now, but I am thinking ahead as I will be getting a car soon)
But I don't want to get an audi or anything super expensive, so I've decided to get either a toyota corolla or camry OR a honda accord - those are really the only cars I like, in terms of looks?

The mpg thing doesn't seem too bad either? I don't understand all the little "EX" "EX-L" etc things? (in the honda anyway, but I think the camry and corolla have something similar to that as well)

Which is better? I don't need that much space since i won't be driving with others very often, maybe a friend or two every once in a while but yeah - after I get my license that is.

The cars I'm talking about are the new 2013 models, I am NOT talking about the accord hybrid plug-in, just the sedan! thanks.
Which is better for a teen? As for mileage, maybe speed? Please list the pros/ cons for each car? thanks - also please don't suggest getting a car that is cheaper - i wanted an audi/ mercedes but no doubt I will mess it up somehow and fixing it will be pricey

what are good mpg things? and speed things? like cylinder? or something i really have no clue!
I am more concerned about mpg, but the speed can be like a bonus?