I like Shaws Cove, it has a protected beach so even on a bad wave day it is usually divable.
Other sites that are good are Divers Cove and Fisherman's Cove, both have easy entry and lots of life to see.
Vis varies at all these beaches from day to day, I have been there when it is 30+ feet vis, and days where it is less than 5 feet. But I always had a good time and saw neat stuff.
I also would strongly suggest diving with someone with beach entry experience, it is very easy to get knocked down in the surf with all that gear on (happens to the best of us) it takes skill and good timing to get in the water at any of these sites some days, some days it is like a pool and it is very easy to get in. Sometimes it's easy to get in, but after an hour of diving you surface and the waves are 5' high. Just remember to exit and enter with your reg in your mouth, it could save your life if you get knocked down.
Another thing that you may have not experienced is surge, the surge at these sites sometimes gets really heavy and can be dangerous if you don't know how to deal with them. Never fight it, go with the flow. Sometimes hanging onto the reef until the surge reverses can save energy. When I first dove in surge I cramped my legs by trying to swim against it, that just made things worse. Again, like surf, surge can get worse during a dive.
Also watch out for urchins, all the Laguna sites are over-run with urchins. I have gotten stuck many times. Wear good gloves and watch where you put your hands when the surge forces you too close to the reef.
In addition to the problems in the water, you need to go up and down allot of steps from your car to the beach. With gear this can be pretty strenious. Take it easy, stop and rest half-way if needed. On hot days with a 7 mil suit and all the heavy gear I feel like I am going to pass out.
I last dove at Divers Cove on Easter Sunday, had a blast, at one point there were about 200 fish surrounding me and my buddy begging for an urchin busting handout (there are so many urchins there, I don't think I upset the ecosystem by feeding one or two to the fish). we also saw a huge Bat Ray.
These are nice beaches too, so after a dive it's nice to play around at the beach, look at tide-pools, etc.
My website has some pictures taken at Laguna Sites. It is at:
http://www.socaldivevideos.com .
Cheers,
MikeT