Agree with Jim - magalluf has a bad press (normally from people who have never been) when in truth it is a very popular resort, for the simple fact that it has everything you need for an enjoyable holiday - good choice of hotels, Waterparks, Pirates, BCM, Kart racing and a huge variety of different Bars, Restaurants and Clubs (although I accept that's not what you want)
There is a part of Magalluf - the Hill, or Strip, or whatever you want to call it, that is very busy, and maybe rowdy in the height of the season, but most people who don't like that sort of scene, simply choose to stay in the centre of Magalluf, where the pace is similar to most of the other resorts that have been mentioned.
Palma Nova is nice, and a lot quieter, but frankly the majority of people there will be 2 to 3 times your age, and you might find it a little too "gentile", although in truth it's only a few minutes walk to Magalluf, where I promise you, you will want to spend most of your time.
Some of the other resorts are lovely family resorts, but that sometimes means having to put up with lots of families with screaming kids next to your table wherever you go - not for me thanks.
Palma Nova and Magaluf are ideally placed for the airport - only maybe 20 minutes drive away, and there is a variety of hotels - I promise you, you'll enjoy whichever resort you visit.
Cheers
Adam