We're pretty gross in our house, to be fair, but it's just the two of us (at the moment) and I'm going to try and improve when baby arrives...yes, I do appreciate the irony of that statement...I mean eventually! 
-change duvet covers/sheets: probably monthly/every 6 weeks. Used to be a lot longer. I kind of like our stank on the bedsheets; I find it calming and comforting. I can't settle in clean-smelling bedsheets- maybe it's a primal/animal scent type thing?
-change tea towels: once a week cos I bung them in with the laundry
-Hoover: twice a week (when we can be arsed)
-mop: what's that??
-clean windows: more frequently than we used to, since we had new double glazing put in and now have a mould problem...
But as for the outside? Literally only when they are so black that they block out light, then we pay someone else to do it.
-change towels: again, every 4-6 weeks. But we do dry and air them in between uses, they don't get slung on the floor/in a basket. And if we have guests they always get clean towels & bedding. Of course!
I know that this falls short of some peoples' standards, but we both work full-time long hours and neither of us can be arsed to do chores when we do have free time! Although, I am feeling a bit more 'nesty' with the pregnancy so I am doing a bit more than usual.
Although, I am a real fascist when it comes to washing up (for some reason). My washing up standards are immaculate! You'll never find a tea stained cup or dried egg fork in my house. All cutlery/crockery is absolutely mint. Isn't it weird? Maybe it's because I used to do silver service waitressing part-time when I was at Uni, so got into the habit of polishing cutlery, etc. MIL is super houseproud- spends all her time cleaning/tidying/redecorating, but every time we go there to eat she has dirty cutlery, glasses or plates. She blames the dishwasher. It still makes me feel better!