If possible, please list the faces and give a brief explanation :)
Any extra content always helps!
Thanks guys!
-Chad

Typefaces popular in America, that’s OK, but for which use? (billboards, print ads, books, web, corporate documents?)
And, 2011, seriously? Two whole months and half?

I'm curious about the rise and fall of popular faces per area.

Then why don't you do some research?
For instance, for a particular area, look at the advertising done by certain sector-leading companies a few years ago, and compare it with today. You would need to go to a library and look at back issues of magazines, and identify the typefaces used. Or use the Wayback machine. Is that too much like work? As a form of 'research', asking for opinions at an online forum is pathetic.

If the learning outcome is to identify what's popular and make a poster using it, just download one of Jos' free Museos from MyFonts and get to work. Tip: all caps, bold sans serif. That should be good for at least a B.