I say go near the end of February and catch Mardi Gras. Temps are 55-75. In the morning, you wear two t-shirts. In the afternoon, it's perfect, and all the water rides work. Crowds are light, and Mardi Gras doesn't cause huge crowds. Mardi Gras is weird, the day happens early in February (8th, 2005), then all the parks and local places run their advertising thru March, even though the day has long since passed. That's why February is good, because Mardi Gras comes, and no one even knows about it. Check the concert schedule to see if someone you like is playing, but even that's up in the air until the last minute.