Four star would be just as good. It's true that you basically just sleep in the hotel and spend more time out and sightseeing. I also think it's what you are used to. I've stayed in a five star once and that was my honeymoon. Now I check to see if the hotel is clean, affordable and has good ratings.
Yup, that's basically my strategy too! One of the best hotels I've stayed in was a 3 star hotel in Vietnam that was highly rated on Trip Advisor. It was clean, functional and in a good location, with lovely staff and free breakfast - it just didn't have all the bells and whistles that a 5 star hotel had. And that was fine by me, especially for the price! It was only around $25-30 US dollars a night!!
Wow! That's a fantastic deal. I feel bad now for only insisting on 5/4 star hotels when I visited India, as I thought that the rest were going to be shabby buildings ridden with squalor. Man, how I was wrong.
Although I did find that a 3 star hotel that a friend was staying in had no sort of cooling system whatsoever! For the entirety of the trip he couldn't get any sleep because it was simply too hot - so remember to ensure that your room has A/C, etc!
I never stay in 5 star hotels. I like hotels off the beaten path and not so close to the city and all the noise. I find them much more friendly and enjoyable. After a day or so the people who work there know your name. They are always there to welcome you when you return.