Circular Dining Room at the Hotel Hershey
I ate in their smaller dining room and it was good. Not great, but good. I assume that they use the same kitchen. The special chocolate martini was amazing though, and I am not usually an admirer.
We visited the circular dining room to check it out and it was very formal and nicely decorated. They were having a Sunday buffet that looked great, but from what I remember it seemed overpriced. Maybe $40? It had lots of seafood options.
I highly recommend booking a spa service at their spa. The chocolate massage is awesome and we enjoyed relaxing by the pool.
I really don't think that it is a place that you go for great food. It's more the surrounding area and the "chocolate experience" that is appealing.
The Circular Dining Room is good, but pricey. If you're looking for a really good meal in that area, try Al Mediterraneo in Hummelstown, which is the town next to Hershey. Al Med is Italian (not red sauce, "real" Italian); the owner is from Sicily, and you can get a casual dinner (great brick-oven pizzas) or a more elaborate one.
I had lunch at the Circular Dining Room about a year ago and was disappointed. Part of the problem was my fault: I didn't know that lunch was a buffet. For a buffet, food was good, but expensive. The room is very nice and the view should be especially nice this time of year with the gardens blooming. While I wouldn't call it fine dining, it's probably as close as you can get to it in the Hershey area.
My wife and I have stayed overnight in Hershey several times but none more recently than two years ago. It is difficult to find a good restaurant in Hershey. The food in the circular dining room at the Hotel Hershey is probably the best in Hershey but also the most expensive. It is one of those "nice to do it once" restaurants. The only other restaurant that we enjoyed in Hershey is DeMarco's downtown. The last time we stayed in Hershey we went into Harrisburg to eat but that is a bit of a hassel. (Thanks profjmm for the Al Med recommendation in case we go to Hershey again. Sounds worth a try.)
Their brunch is well worth the time and money to enjoy. They always have something different, and the dessert table is swoon-worthy.
There are a number of good restaurants in the Hummelstown-Hershey-Palmyra area. Al Meditteraneo is one, but there's also the Warwick Hotel in Hummelstown, the Hershey Pantry, Lisa's Cafe in Palmyra, and the Batdorf Restaurant in Annville, just outside Palmyra.