My favorite position is missionary but with a twist. I have my girlfriend try and put her head as close to the edge of the bed that is still comfortable and supportive of her neck. She then moves her hair back and her hair is essentially at this point flowing off of the bed, all of it, down to almost the floor. I get on top of her and make love to her in this missionary position but with the added bonus of being able to wildly run my hands through her long mane and to stroke and grab and play with all of her hair as much as possible while I am inside of her. Bonus would be at times I am able to see her hair sway and move as I make love to her, or I am able to see myself stroke her hair while inside of her, both of which turn me on to no end.