When will you be traveling?
Atlantis had a long line (60 min) when we were there July 22-23 but the Brazilian tour groups were part of that. We had QQ so we carried on. Kraken was always pretty quick unless you wanted front row, though by the second week that was walk on, even front row. We saw Manta have as long as 40. The shortest we saw posted was 15 but it was really like 5.
I agree with a PP about Aquatica. Do everything once you get there as far as slides go, then repeat ones you like. The longest wait we had was 30 minutes for the one that goes through the Commerson dolphin tank /Dophin Plunge. The fastest/shortest lines were Taumata Racers (8 people go at once) and the Whanau slide (multi-riders - four (?) slides.