I have been debating this for weeks!!!

I have the opportunity to move anywhere in the U.S. for my job.

I am looking for somewhere:

1. Close to a major (top 50) market cities. (within 1 hour to actually live from the city and no more than 4 hours from the "ideal" lake,
2. Great Boating for a 38' offshore boat. Get some serious runs in.
3. When boating, lots to do: place that has, for example some of these things: shore power, bars, tons of partying, things to see (beautiful environment)... just sitting out in the middle of the lake tied up isn't my ideal situation
4. Close to at least 1 lake (4 hours or less that fits the above description)
5. Nice to have a change of seasons but open (Phoenix, for example, doesn't have a change of seasons and I am seriously considering it)

Been thinking about Phoenix and Denver. What are the pros and cons of these cities and WHAT ELSE IS OUT THERE????

I really can't find anywhere on the web that lists all the U.S. large lakes that tells you if they are more "party" lakes. Can find a lot for snow skiing but not boating.

Lake of the Ozarks

Newport Beach, play in the big lake pacific.

Lake of Mexico
All of your criteria are met, Tampa is a well within the top 50.
The Other Big Lake is less than 4 hours away.

No question...south florida.

Lake of the Ozarks in central MO

Lake Havasu, AZ

Lake Travis near Austin, TX

Sandusky Ohio or the surrounding area.
Lake Erie will provide some great 38' Offshore water
Lake St Clair and Lake Michigan will also be within your range.
Some nice boating clubs with fantastic poker runs and friends.
Lake Erie Islands provide some major adult entertainment
Cleveland and Detroit are both within a 1 to 2 hour easy run by boat (more entertainment).
Leamington Canada and other nice Canadian ports are within 1 to 1.5 hours
Approx drive times (by land) to the cities below
Detroit 1.5 hours
Cleveland 1 hour
Chicago 3.5 hours
Toledo 1 hour
Cincinnati 3 hours

A lot of different things to do and you don't always have to go to the same two places every weekend. A lot of ports and some great sometimes challenging water make it IN MY OPINION one of the best places for what you have described. I travel a lot and have seen some beautiful areas but still would not want to move till I am too old to deal with the winter weather that also offers a lot of snowmobiling and skiing in the nearby areas.
BTW Cedar Point is also located there.
I will now forward this to the Sandusky Visitors and Convention Bureau and ask for my commission check.

BTW, you can call your friends up north in January and tell 'em "What a great day it was out on the boat today!"

If I were in your shoes, I'd be looking in South Florida myself, but I'm partial to "Lake Atlantic."

Denver is a great place for most sports except for large os boating, there was a tread a while back from a guy going there
on vacation and from my recollection no one could point him towards a decent lake to put in at that was not several hours away from there.
Scott's right about the great lakes Ohio, MI area, there are a zillion places to go, but the season is sooooooooooo short.
Pity about Denver though, I'm and avid snow skier, so I would love to live there some day, but no real big lakes.