The beaches suck and are crowded, but the beach towns and boardwalks are great. Get yourself a tacky Jersey Shore shirt, and since you're a Jeep guy, check out Menantico in Millville. (Great offroading spot)
And if you're near Trenton/Robbinsville, stop at DeLorenzo's and get yourself a pizza pie. (sausage w/ extra tomato)
Your not going to the right ones then LBI is quiet and family oriented and there is plenty of room to lay out your beach towel. Drive all the way down to the southern tip and its so sparse you might get board. Good beaches down in Cape May to.
Forget the beaches. The Jersey shore sucks. Stick to the West side of the state and go hiking in the Appalachians, or tubing down the Delaware, or camping in any of the awesome state parks.
The beaches! If your not into the boardwalks then check out Long Beach Island. Very clean and family oriented. I lived there for a few years and loved it! Also there's tons of trails to wander around on in the Pine Barrens. I'd suggest getting a local Jeeper to go with ya though as it's very easy to get lost in there.