In terms of wind/season/view...
Lake Arenal overlooking Arenal Volcano in Costa Rica has some killer wind for kitesurfing. The west end is the windiest and it's known for having consistent gusts of 30 mph--best during the dry season (Dec.-Mar.). It's an awesome area to explore too, with the volcano, the La Fortuna Waterfall, great hiking, hanging bridges, and lots of wildlife like monkeys, birds, etc. Oceanside, Bahia Salinas in Guanacaste is supposed to be great too. Probably lots more spots around the world but those are two in Costa Rica.
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Caye Caulker, Belize has a lot of kite surfing. And it is a fantastic place!
Some details here: Just a Pack's Top Ten Things to do in Caye Caulker
I hear Fuerteventura in the Canary Islands is great. Loads of people doing that when I visited. Also, they have the Windsurfing and Kiteboarding World Cup there.
I recently learnt to kitesurf at Paje beach in Zanzibar. Amazing 'lagoon' formed by the reef about a mile out which gives you several miles of calm knee-to-waist deep water which is perfect for learning in. Consistent winds as well!
I don't kitesurf, though I want to get into it. I can't imagine a better place than this beach in Cape Town. I snapped these photos when I was there and have always dreamed to return.