Well. The mama-papa (missionary) position comes (no pun intended) with a lot of advantages: head-to-toe (or nearly) skin-on-skin contact, lots of penetration, ease of kissing during the act, the list goes on. But, admittedly, after forty life on the bottom takes on a definite appeal: gravity is your friend, everything you like is right there in front of you, et c. The smart (and safe) answer would be I never had sex where I'd rather have been doing it any other way.
Favorite time of day to make love?