One thing to keep in mind is that graduate school is not merely an extension of your undergraduate experience. The coursework phase is brief (usually 2 years, sometimes 3 depending on your program). Even at huge R1 universities, graduate level course offerings tend to be limited and of a very uneven quality.
You might be excited about the prospect of taking grad seminars now, but once you're a few months into it you'll probably find yourself eager to move on to quals/prelims, research, and dissertation writing. Don't go around thinking grad school is all about the coursework; it really isn't at all.
Here's a suggestion: be extremely selective about the courses you take. If the course offerings don't jive well with your research interests, enroll in independent reading courses instead. This is especially important if the professors you want to work with aren't teaching graduate classes. The coursework phase isn't so much about absorbing new material, it's about making good faculty connections.