I agree with the idea that it depends on what you want to do with it. Some people want luxury and pampering. Some want flexibility (like a points program). Some explore a lot of destination locations. Some just want comfort, space and seclusion for family time or relaxation. Some families love tons of sports and activities. Determining your priorities makes a huge difference in what you would consider the "best."
Of course, DVC provides lovely, luxurious, fun resorts in a few delightful locations.
For fairly consistent luxury and a wide variety of locations, Marriott is excellent.
Hilton/HGVC offers a few terrific resorts in southwest FL, HI and Las Vegas.
In Cancun, Mexico, the Royals are tops for sports, pampering and amenities.
For points flexibility with a very large system of good resorts, Fairfield is wonderful on the east coast of the U.S. and WorldMark is wonderful on the west coast of the U.S./Canada (each with a few additional locations elsewhere).
Sunterra offers a lot of resorts in a very wide range of places but they seem to vary more in resort quality.
There are other points programs as well.
For Europe, there are several large companies but I don't know much about them. Hawaii has nice PAHIO and Shell resorts. Visit
TUG - Timeshare Users Group to learn more about timeshares and ask a lot of questions. HTH!
