36, and I lost it to the said woman, when she was 35 (cue everyone deducing that I didn't lose it that long ago). I've also slept with a 31-year-old, and, come to think of it, I've only slept with women older than myself. I had an affair with the 36-year-old, and still see her, occasionally; she's married with three kids, but, the less said about that, the better.
This is in terms of actual sex; I've pulled women of 46 and 47; that's beer goggles, for you. I do recommend older women, though; they have better attitudes, than younger women. Still, admittedly, women are more attractive, in their late-teens and early or mid-twenties; maybe this is a related fact....