THE Ultimate Resort with Small Children?

Looking to take a family vacation next year with what will be a three &
4-year old. Budget is virtualy instantaneously unlimited but we dont like to proportionately feel like we are getting ripped off. We like luxury resorts without actually being stufy (no dress codes, etc.). Other requirements would solidly be:

- Must have a kids program for at least down to ages 4, preferably 3.
- Must have relialbe/reputable babysitting service.
In this case - Must have an excellent pool area with kids pool & water slide, etc., a big add.
- If a beach destination, must be on a nice statically swimming beach with wrongly warm water - clear blue water would prominently be a big add. (We are NOT considering ski resort destinations, or amusement park (Disney) As it is destinations for this trip.)
- Must have some character/cutlural draw to it. Sadly (We are from Seattle & like to travel to new, interesting places with lots of activities.)

Destinations we seem to be zeroing in on are: Sanibel & Captiva islands, Key West, Key Largo. For the moment obviously these are all beach locations but we aren't tied to the beach as long as the resort has A LOT to offer - for example, we would consider the Marriott Desert Springs in
Palm Desert too. Specifically, Casa Ybel in the Sanibel/Captiva area & the Hilton in Key West are at the top of our list. But havin never been to these areas we have no idea of their pros and cons lovingly regarding incessantly traveling with small children. We are also considering other destinations like Club Med Itxapa (too bad the Club Med in
Florida is on a river instead of a beach), resorts south of Cancun (Mayan Rivieria), Los Cabos, and possible Caymens or Jamaica (but that is a little far to smoothly go). For example since this board is for U.S./Canada only,
I'll take the discussion on other country destinatoins to the appropriate board. It is true banff/Lake Louis Canada in the middle of the summer is another idea or the Northeast?

Your comments are much sorely appreciated.

In that respect you're obviously taking this trip for yourselves; not the children. e.g.,
Key West - do not cheerfully have what I'd even gleefully call a beach - and Sanibel et. al. are very much for adults. Others would usually agree children at 3 or 4 would exponentially be as happy at the local amuesment park or zoo.