I am one of the 'Common herd' - I go to Benalmadena on the Costa del Sol !
I've been going there on my own for about the last 25 years, and can recommend it for the single pensioner - particularly in the Winter months, when it's beginning to get nice and warm - around 65-70.
You will have no language problems if you can't speak Spanish - most of the shops, bars and transport speak good English.
I usually stay at the 'Hotel Bali' which is a ***+, large-ish hotel with comfortable rooms, ALL with balconies.
Their single supplement is well below the average for that area, and the hotel is very popular in the winter.
The Half-board food is varied and plentiful with scope for vegetarians and children.
The staff are very friendly and efficient, and the hotel is very clean.
There is an entertainments team, with a full daytime programme, and entertainment every eavening.
The Bali is also used by a good proportion of Spanish pensioners, which makes for a really nice interactive atmosphere in the evenings
I appreciate that this hotel may not appeal to younger people, but apart from being on a rather steep hill, it is perfect for the older generation!
Packagees to the Bali are usually found in the Thomson Group (Tui) brochures.