The oddest thing is I can understand why people are suggesting Hitler. He was one of the evillest men in history, but he must have had something going for him to manage to gain his level of influence. I wouldn't want him at large in modern society so I wouldn't resurrect him, if however I was being offered the chance to meet him, I might take that offer.
I just know someone famous could be a disappointment, so I'm picking a Barry the maintenance bloke from a factory I used to work in and my cat Chaplin. Two individuals who I know would be welcomed back with open arms.
I actually think, despite what he did, he would be an interesting one to resurrect. I mean, nobody wants crazed zombie nazis, but in a studied environment.
I guess it would be interesting to see what he would make of the world now, and to see the effect of just what he did, and how he has become one of the most notorious characters in all of history. I'm sure he didn't see that at the time. Also, he was never made fully accountable for his actions, as he killed himself to escape them, so would be good to bring him back if anything, just to stand trial for his crimes.