My brother and I are doing a week-long disc golf trip in mid-August to play a lot of the PA/NY/NJ/DE courses, many of which are supposed to be just stunning.
We'll get in all 54 holes at Codorus (PA), the 36 holes at Pinchot State Park (PA), all the 2005 Pro Worlds courses in PA (Jordan Creek, Little Lehigh, Nockamixon, Tinicum), Warwick (NY), Campgaw (NJ), Tyler State Park (PA), Brandywine (DE), and Iron Hill (DE).
We're skipping some obvious great courses that should go in that loop because we've been to then before (Seneca and Patapsco in MD, Whispering Falls in PA, The Woodshed and Whipping Post in WV, etc...).
I think that if I could head anywhere, it would be Minnesota, but depending on what your flights and other arrangements look like, it is worth considering what fits your budget and schedule, and its worth having several options depending on where the flights are cheapest the week you want to go.
I would also recommend NC/SC/GA as a great option -- make the short loop from Charlotte to Augusta, and hit up Raleigh as well if you have time -- some amazing courses in all three places, many of which are legendary.
Another option would include a Massachusetts week, with Maple Hills, Pyramids, Buffumville Dam, Borderlands, Barre Falls, and some nearby courses in VT, CT and RI as additional courses.
If you just want a great vacation, then the SF Bay Area is worth considering -- a handful of top-shelf courses there, including DeLaveaga and Golden Gate Park, but also stunning weather, beautiful vistas, wine country, microbreweries, and lots of great camping and hiking. It's not where I would go for a disc golf only excursion, but definitely a place I would consider for an overall awesome vacation. Same goes for Seattle and Portland -- a handful of awesome, awesome, awesome courses, but also a lot of other diversions if you want a break from DG.
The other thing to consider is what your home courses are like. Do you want courses that are similar or courses that are entirely different? Different parts of the country seem to have their own flavor when it comes to their courses. Think about what you want out of your trip.
Also, do you want to go to a handful of courses and just relax, enjoy, soak in the beauty, play the best courses 2-3 times each; or do you want to rush around and hit as many courses as possible?
My favorite disc golf retreat is Paw Paw in WV -- two world-class courses on the same bit of private land. Some of the best camping I know of and some of the friendliest people as your hosts. It's a place you can pitch your tents, leave the car unlocked, build a campfire, play beer-in-hand the whole time, swim in the pond, just r-e-l-a-x. And shoot on two of the best SSA-64 courses I know of, with a crazy mix of woods, open shots, and elevation changes. For sheer enjoyment, I'd plan a trip that started in Pittsburgh, played the 3-4 world-class courses near Pittsburgh (Moraine, Knob Hill, others...), then headed down to stay at PawPaw for two or three days. Then make sure to hit Whispering Falls on the way back up to Pittsburgh, and hit anything else you can to round out your trip. That would be a relaxing week... all the golf you want, but also several zero-stress days with no hotels or traffic to worry about: just you and the discs.
