I want all of these features, but I'd be very upset if I can't have my beautiful fantasy scuba dive lots.
A resort system would be seriously fun and useful across all worlds, so I'd choose this as my second favourite feature.
I'd rather have the ability to build on the water (stilted foundations) than live on a boat, although I obviously would looove a houseboat.
Mermaids would be a fun feature. I'd admittedly not play with them much if they are done like in TS3, but if they can actually live underwater (which is unlikely), they'd be really cool.
