I would pick Tenerife. We tried Maderia one December. The place itself is lovely and the temperature was great, Hotel fabulous. . However, there were a great deal of very, very elderly people there, lots of mobility scooters and walking sticks. I don't mind elderly people. I am getting there myself, but I like a mix of ages on holiday. There was also very little to do in the evenings. There was ballroom dancing in our Hotel but not much else. We had some nice meals out and the restaurants were very good. However, it seemed most of the visitors went to bed early.
We took a day trip around the island and had a wonderful trip on a mini bus. We were the youngest ones on the trip. Most of the others had been coming for years every Winter and one man of 85 was a great fun, he had so many stories to tell us and we never stopped laughing all day.
Have to say though, we booked for a week, but 4 days would have been enough. Everyone told us we should have come for N.Y as it was fabulous then with all the fireworks.