It is a general consensus that sleeping on your back
is the most advantageous simply because your back is aligned properly and there is no strain to your body. However, this is problematic for those who snore and your partner will more than likely want you to roll over and hang tight to the blankets in the process.
You are the master of your sleep position. What works best for you and your partner is what you will want to stick with. So sleep well, that's the goal.