I'd come back as some sort of cyborg being. A kind of gelly mixture one the inside, like a brain, and a BioTechnical Steel-silver armor on the outside.
I would like to come back as a priest. I really like the care and work these people do for the society.. There are the actually human beings who live their life in full stretch.
If I would be reincarnated, It would be a person, if I still knew my past life. If not, then I would want to be reincarnated as my son(If I ever have one)
Reasons: I always had big dreams, I wanted to make great games, movies, to program, and all that other stuff. Though I know for one that I could not do all of this in my life, so If I would be a reincarny, I would be my son (then I would give him all possible things to fulfill his (which is my) dream)
Personally, I'd want to be a Bombardier beetle. They are carnivorous beetles that shoot 212-degree Farenheit caustic chemicals out of abdominal glands.