Well Playa den Bossa would suit you perfectly, there's a super Blue-flagged beach - very long, and several discos there, it's a 10min ride from the airport so you do hear planes, kids would love it.
Salou in Costa Dorada is lovely (in spain), and Thomson do some really good deals, we stayed at a hotel called Hotel Calypso - which was about a 10/15 minute walk to the beach.
Its lively and has nice restaurants and the clubs seemed nice and really good shops!
Plus the other good thing is its right next to a big universal theme park called "PortAventura" which is ace there is also a water park there, there are frequent buses from all round Salou and they are really cheap - you can get 7 day passes into the park which gives you 'fast track' into the rides so you can skip the queues!!
There's also a market on every day of the week around salou.
Thomson had quite a few excursions you could book to go on like swimming with sealions and such like which a lot of the families went on.
im 18 and went with my boyfriend a few weeks ago and we loved it!! can't wait to go again!!
By the way, in Playa den Bossa there is also a big water park, and lots of modern shops, cafes, bars, restaurants, everything needed for that perfet holiday for teens. Don't know of any all-inclusive, but I'm sure there must be some. Good luck.