We went for our anniversary in Oct. We stayed at the Brock plaza. It was beautiful. But be warned, the hotel is very old and the rooms very small. We actually had a key, not a card but a key! I had never seen that in a hotel before. The rooms were beautiful and very centrally located. The service was fantastic and the hotel beautifully decorated. We were looking to be cozy anyway! In less than 5 mins we could walk to the falls, Victoria Hill (the main drag with all the cheesy fun touristy things), and numerous restaurants.
One thing I will mention is that we found it hard to find places to eat. We are not fans of HardRock, Rainforest Cafe etc. We find them WAY overpriced for the poor service and mediocre food. I have no problem eating at a Kelsey's at home but found they were much more expensive there. We sat down at Planet Hollywood (hardly my idea of a romantic anniversary dinner but we it was late and we were having trouble deciding on a place), read the menu and left. Spaghetti was $15 and a martini was $8! We ended up at a place called Monticello's which was outstanding. The service was fantastic, the food to die for and the atmosphere was perfect for a romantic dinner. It was a little pricey (my veal entree was approx $20) but I didn't feel that bad after realizing I would have paid the same for fajitas at PH. My DH had the muscles and he still raved about tham. To find it you would go up Victoria hill to the 1st main intersection and then turn right. It was approx half a block up on the left hand side of the street.
If that is not your style there was Kelsey's, Perkin's and several others very close by. There was also a beautiful restaurant in the Brock and it is also attached to the Sheraton which I am sure has a restaurant. The restaurant in the hotel overlooks the falls as you eat.