I'm surprised nobody's thought to mention Southern California! You can do all the shore diving you want here, and there are plenty of dive ops close to shore diving sites where you can rent gear and get fills. There are also many fantastic dive boats that will take you out to the Channel Islands and other aweseome diving locations (e.g. Farnsworth Banks, the oil rigs) that not only allow you to dive without a babysitting DM - they expect you to! Unless you bring your own DM, you will be on your own. Most boats do have gate times, but they are generally more than long enough for you to breathe out your tank on each dive.
Yeah, granted it's not exactly warm-water coral reef diving out here, but we have our own special gifts - namely, kelp! Kelp diving is an experience that should not be missed.
Around the Christmas holidays is a great time for SoCal diving. The conditions are often excellent, the water is a reasonable temp, and it's right in the heart of lobster season - you can go bug hunting!
There are fantastic hotels and resorts (not dive-related, but just lovely places) in Malibu, Laguna Beach, and San Diego, all within close driving distance from top-notch shore dive sites and dive boats.
No I don't work for the California Bureau of Tourism - I'm just a fan of our local diving - and grateful that we get to do all the diving we want without having to be led by the nose by babysitting DMs!