Here is my two cents on the Coronado Hotels listed in the above reply. Since I live near San Diego, I've been to these three places several times and they are all great hotels, you won't be disappointed with any of them. However, their styles are completely different so your choice should be based upon what type of hotel you prefer.
Hotel Del Coronado: Beautiful old hotel, with lots of history and antiques in the public areas. It has its own tennis courts and beach access. However, its probably the most expensive and not necessarily worth the money. Soem of the rooms are dark and small, unless you pay the Really big bucks to stay in an oceanfront room. If you stay at either of the other hotels mentioned (the marriot and Loews - also in Coronado) you can walk thru and tour the Hotel Del to see the history, etc.
Marriott: Of the three hotels, its the most affordable (relatively speaking) and is conveniently located to other fun things/restarants in Coronado. Downside is they don't have the best beach access, but the beach is close by. This hotel is more business-crowd oriented and less "resort" feeling.
Loes Coronado: Really cool hotel with a great pool, its a more modern and upscale property (less stuffy, more fun than Hotel Del). Even the standard rooms are luxuriously appointed, with upscale decorations. The rooms are larger than the Hotel Del. The only down side is the location of the property. It is down the straight about 1-2 miles, and there's really nothing within walking distance around it. That's OK if you have a car or if you are just going to stay on the site. They do have a water taxi that takes you across the Bay to Sea Port Village (in San Diego). This would be my choice for the best accomodations amoung the three Coronado hotels listed by the previous poster.
Hope this helps you some. Enjoy your stay in San Diego. Its a beautiful city!