If life was perfect and other activities weren't around (that are just as much fun and fulfilling) then up to three times a day would be amazing. Maybe more. Day to day would be lounging around and cuddling and generally exploring the nature of time in small traces of fingertips on skin.
I'm on a long dry streak though, because I'm in an area dominated by conservative assholes, and I'm really not the type to go to bars or other hookup type spots (I'm a romantic [and very slow in relationships] and shy and generally paranoid, sue me) in the one small queer area that exists. Way too concerned that people in that area are getting scoped out and tracked now. So, tangent aside, I can obviously do with way less than once per week. I think I'd be happy if a partner was generally up for two or three times per week of actual sex, but massages and cuddling are daily mandatory events. I like to touch and be touched.
Edit: plus, the 'quality' of the sexual activity will matter greatly. As much as I love choking on someone's horse-sized phallus, I doubt I could keep up with that multiple times a day. I'm pretty sure my dentist has commented without commenting directly on it, asking about some bruising. Boy howdy, was that a surprise. Same with the cunnilingus: my face and tongue just can't keep up; it is incredibly tiring and induces sore muscles like nobody's business.