Congrats on your decision. I am a life-long Texan. Attended college in Oklahoma. Have a brother who traded Texas for Tennessee quite a few years ago, because his college sweetheart wife is from there.
From my own knowledge and experience, I would wholeheartedly recommend Texas(if you pick your spots, as it is rather varied), Oklahoma or Tennessee. I was born in Fort Worth, TX, but have spent more of my life in West Texas - San Angelo and Abilene. I went to college in Edmond, OK(near OKCity). My brother lives in Columbia, TN, about 30 miles south of Nashville.
Good luck and God Bless.
Thanks. We're heading to Tennesse this weekend to check out the area.