Hmm, seafront show. Planes are a "mile" off and on the grounds itself there's not much interesting to see most of time. Surely worth a visit, but not something I would travel more than a few hours for...
If you are in the UK, I would recommend: RIAT (Fairford, RAF/USAF), Duxford (warbirds) Waddington (RAF), Farnborough (trade, lots of new stuff), Yeovilton (RN)... and Leuchars, but that's in September and in Scotland...