T.F.
Congratulations! We just celebrated 20 yrs on New Years Eve.
Downtown Dallas has some great places....Hotel Zaza (some themed rooms, spa, great bar and nice restaurant, walking distance of some nice places) the W, Crescent (nice spa, walking distance to so nice things) Adolphus (home of the French Room which is SO good....men must wear a jacket...excellent service)
A friend of mine enjoyed a weekend at the Gaylord. It is a nice place.
You can get on the hotel websites for information, booking and pricing and/or call them directly for great rates.
Whatever you do.........Enjoy!