They may not be offering the stellar discounts they were doing earlier this year, but in my opinon even the regular adult ticket for $80 with the second day free within seven days is still one of the best ticket deals in Orlando, especially if you love the Sea World parks like we do and like doing two days there during your trip. Sometimes too it is worth it to have one person in your party get an annual pass for free parking and a 10% discount on food and souviners. When we had a large group, we'd have the person with the season pass buy all the food and souviners, and we just reimbursed them.
To get your ticket for the second day free, you need to stop by the customer service desk on the day of your first visit. We usually do this sometime in the afternoon to avoid the crowds near the end of the day.
This is our favorite park in Orlando, and we think it offers an excellent value even at normal prices.
I, though, always love discounts so will keep an eye on this post too. I currently have a two year season pass, but will be purchasing some tickets for others who don't have season passes in March.
Web site for normal ticket prices
http://www.seaworld.com/Tickets/Visitors.aspx
Another option, especially if you are just doing SeaWorld and are just doing a short Orlando stay is to look at some of the hotel packages that offer Sea World tickets. One time I was planning to stay at a hotel near Sea World anyway, and the package deal they had for $50 more than I would have spent on my room ($25 per night) gave me two SeaWorld tickets. It was perfect for us on that trip.