In general, I really like having slope in my backyard. Not a huge believer in feng shui but I have heard it is a great feng shui to have slope (something to do with good financial growth ;-))
If you keep the slope with appropriate plants, trees and greenery, it will really look great. As everyone said, just make sure the house on top of the hill is not directly overlooking your backyard. You could grow trees at the top to hide that as well.
Having a retaining wall with proper drainage will do the trick. Depending on the size of the slope, I have even seen some folks built stairs and seating area in the middle, again I am not a huge fan of that either. It’s just more land for you to play with…
