I was there, Benidorm, for a week last September.
I had a great time, I was on my own, but never alone unless I wanted to be.
It can be as 'common as muck' whatever that is, the folk who holiday there are predominantly from Northern England and working class. If that upsets you, don't go.
I stayed here, which I have to recommend, as it is owned by a friend of mine. http://www.babylonbenidorm.com/
Benidorm Old Town is as gay as gay can be and right on some nice beaches.
The New Town isn't very nice, with no gay presence at all, I'd stay away. Its a distance too.