Most Helpful Guy
Open sky, preferably near an ocean with a full moon
Most Helpful Girl
I don't think the location itself could determine how romantic the evening is. The best nights with my boyfriend were at his place, where I could see how much effort he had put into cooking dinner just the way I like it, downloading the movie I'd mentioned I had wanted to see, etc..
Doesn't hurt that at home, the option of having some more 'intimate' moments is most convenient, as well. ;)