If you want beach front, you definitely want to stay at the Del. Awesome hotel- I like the modern tower rooms, where you can walk out of your room and have the beach RIGHT THERE, and the quiet lap pool (there's another pool for families by the main building). It's by far one of my favorite hotels in the country. The only downside is that it's about a 20 minute drive from San Diego's downtown- but Coronado has a cute little downtown of its own, with some nice restaurants and shops. The Coronado downtown is right next to the Del, so it's a very easy walk.

Also, if you're really into getting miles... the Del shows up as a choice under iDine's Hotels section, although it can be hard getting availability. It also often shows up on Expedia at decent rates, especially in shoulder seasons.