IMO, this question is like asking "How often would you like to have a yummy meal?". My answer would depend on "Who's doing the cooking or paying?" and/or "What's on the menu or how will you tempt my appetite?". If you are loading me in the car and driving to buy me sushi on Monday and pouring me a cup of coffee and setting out cookies on Tuesday etc. etc. then I would say every day (at least). If I'm usually making you your favorite corned beef and/or spending my pennies on Italian but you are appreciative, maybe every couple days or 3x a week. Since, according to the polls, most men prefer to initiate about 2/3 of the time, and I'm liking that ratio too, my ideal would probably be about 4-6X a week.
"Tell me, what is it you plan to do with your one wild and precious life?" - Mary Oliver