Most Helpful Guy
Generally the idea of going half your age plus 7 years is a good idea. Therefore, I'd have to go no younger than 23/24. I'd say 23 - 24 would be the youngest, which is fine for me.
Most Helpful Girl
I would date a guy a year younger than me if he's quite mature. I'm in that awkward age where the mental age gap between guys and girls is often really big.
I wouldn't like a guy who thonks smoking, drinking and doing drugs is so awesome and you're not cool if you don't do that and parents are dumb ofcourse.