In general, American tv series don't seem to be comfortable writing about college (as opposed to high school), at least once they work through the three stock plots: not getting along with your roommate in the dorms, an evil fraternity/sorority, an ill-advised affair with a professor.
Note that Buffy and Smallville only got one season out of their heroes' college years, and that Veronica Mars planned to skip over the rest of her college experience had the show been renewed for another season.
Off the top of my head, only Felicity was expressly about going to college for its entire run. Can't remember how much time she actually spent in classes. *
(I dimly remember reading somewhere that TV networks are leery of shows about college because, unlike high school, it's not a universal rite of passage shared by pretty much every tv viewer.)
* There also The Paper Chase, but that was about law school.