I saw your post and question last night just before I went to bed and have continued to think about it.
I love history, and there are so many places that I would love to visit and people that I would love to meet, if I had a time machine. But I can't think of a single time that I would want to stay in for very long. The world has had such turmoil. I would be good at living a pioneer life and living off the land, though and would enjoy a quiet life living on my own homestead.
But if I could go back just a short distance, I would choose to go back 25 years ago when I could still walk with ease and before my MS progressed to the point that it's at now. Being able to walk again would be my wish for a time machine.