American Express - if you have Membership Rewards you can use them for free Busch Gardens tickets (it's a time to time thing but I saw them there just recently). Check other rewards cards!
I got the Super Grover Pass from Sesame Place last year - think this year it's about $150 or so. On sale right now 25% off. It got us free preferred parking (at Busch Gardens, Water Country USA, and Sea World, which saved us $20 each day) plus discounts on food and souvenirs, plus a large discount on Discovery Cove (about $60 per person off). It gets you Aquatica as well. We used it in Orlando and Williamsburg.
I agree to check out mousesavers! She's the best!