There is a big disc golf scene at Sugarbush in the Mad River Valley. They have 2 courses along with some big events - pro events, as well as the national deaf disc golf champsionships there in the summer.
There's a fun course in Waterbury that's worth checking out, and I've heard nothing but great things about the course in Sugarbush (it is a course you pay to use, just as an FYI).
And, there were plans to put a course in Leddy Park in Burlington... but that's a topic I hesitate to even get into. Do a Google search on that issue if you've got a decent 30 minutes to read about that mess, all while scratching your head and saying "Seriously???"
I'm a big fan of the Waterbury course, also the one at Johnson State College, and the one in Randolph as well. Waterbury is long and pretty tough, and Randolph is tight and technical. It's been awhile since I've been to Johnson but I heard they've improved/expanded it quite a bit. The course directory on the PDGA website has pretty much all of the courses in the state listed I think as well if you want more ideas.
It's a shame that they didn't allow that course into Leddy Park. Living in Burlington you need to drive at least 40 minutes to get to the closest disc golf course.
I usually hit the free waterburry course, mainly because it's free and the closest to me.