Any of the hundreds of bikes out there might be the "best" for you. If you are going to require that it have an upright posture, I have no clue. I have a four inch drop from seat to bars. And I'm 62.
Seriously though, if you want an upright posture, and you don't ride for long or hard, then a beach cruiser style bike or a "fat" bike might be the thing instead of a road bike.