My boys (3 and nearly 2) have recently been to both SeaWorld and Dreamworld (due to ILs taking nieces/nephews while they were up visiting so we tagged along with the boys). They loved both. Seaworld obviously has the appeal with seals, dolphins etc but the shows are too long for the boys. Dreamworld they really enjoyed too, with the tigers and the kiddy rides (sea world has kiddy rides too but wiggles world is great and has a whole section which the boys could have played in for hours LOL). I think either would be fine for a 2yo. As long as you're prepared to spend lots of time doing what what he enjoys. Suits me as I hate rides anyway LOL, in fact the kiddy ones are just my speed!!