Tenerife, Marbella, Benalmedina. Don't go to Benidorm or anywhere like that unless you want to sign up for the steretypical Butlins abroad deal.
Or alternatively, book a hotel at a resort nearby to Magaluf, and just go out whatever nights you choose. First year I went Magaluf we stayed in the next resort along (unknowingly), which is about 15 mintues walk from the strip. It was far enough away to get sleep and be away from 24/7 partying, but at the same time close enough to be a part of it if we wished. Hotel had quite a few youngsters doing the same thing, but at the same time quite a few families staying there. The reputation of places like that is blown out of proportion anyway. It has idiots but no more so than on any night out you'd be on in the UK.