Hi Anna
I'd highly recommend Playa Blanca on Lanzarote or Puerto Mogan on Gran Canaria. Have only visited these 2 islands but these 2 resorts have everything you'd need and are quiet and gorgeous.
Lanzaraote has stacks of interesting things to visit & would probably get my vote. PB has great walks along the promenade too. We loved it so much last Easter we're going back in 5 weeks time.... can't wait!
Hope this helps.

Hi Anna, like toastedmallow i'd recommend Playa Blanca, i love it there, its so laid back , great weather, friendly people , good places to eat , not too "english" .
there are all-inclusives there , but i've never stayed in them , when i've checked the prices for a good hotel package i find that i can get flights , a private villa with own pool and eat out every night for the same money.
there are interesting places to visit and i've done some , and i'll do some more next time, and next time!! good excuse for going back!!