If you live near a Target store you may find BOGO free child tix coupon for legoland on lego toys that will only cost you about $4. I read a post about it and saved on 2 children tix and luckily while standing at tix booth this generous lady gave me a free admission ticket and ended up paying for only 2adults and 3 children free which cost me $138. Ticket expires at end of year.
The fun card for Sea World is a good deal if you are going for more than one day (or will be back before the end of the year). Otherwise, try the discount website the PP mentioned.
I just posted a thread about a pretty good deal offered for LL. 5 consecutive days for $79. Inc. Sea Life and their waterpark. It's a Daily Deal and only can be bought until midnight, PST, tonight. Have to use by May 31, 2011
Some on the Dis DVC board posted this link for a Sea World ticket for $39 that can be purchased on April 12th (10% less if you use an Amex card). Looks like ticket is good for more than a year and expires April 30th, 2012.
If you get a free subscription to Lego Magazine, there is a coupon for one free child admission with paid adult admission. They are in every issue. We have two of them so that is an awesome deal IMO.