Or Freddie Mercury, for one last tour. And debauchery of course 
In any case, people from too far back in time would be in for a horrid culture shock. And would definitely be seriously un-PC for our times.
“You have a Moor as King?”
“Yay, verily woman - cover those ankles before someone sees you!”
“What do you mean I can’t beat my children bloody?”
Nicole Brown Simpson and/or Ron Goldman. Get that question answered once and for all.
On a more serious note, Mozart. I think he’d love today’s music scene.
Alfred Bester, from circa when he wrote The Demolished Man. I’d love to see what he could do with modern publishing and graphics.
Van Gogh. . . . just to see the look on his face when he sees what his paintings are going for.
Don’t know if you’re a Doctor Who fan, but that very idea was part of the plot of one of the episodes last season.
Jesus? JESUS???
Are you people cracked? It’s called The SECOND Coming for a reason. Not the third or fourth coming. You bring Jesus into our times and it is the End of the World. You can’t just send him back and say “See you next time!”
Me, I’d go for da Vinci or Jefferson.
I don’t know if we want to go whole hog into Tesla’s beamed power plan. For one thing anyone with an afro more than 53cm across is going to burst into flames.
Damn, you beat me. I’d have to presume she would be very… grateful.
Alan Turing, from before his arrest. I’d love to show him how the digital computer is in everything, and the utter necessity of information theory in today’s world.
I’d also like him to know we’d mostly grown out of the crappy attitudes toward homosexuals.
The problem would be he’d definitely not want to go back, after reading about what they did to him. But maybe knowing the future would keep him from suicide if he did return.
Edit to add: Say, could I return him to his own time in the States, instead of the U.K.? Still not enlightened at the time, but I think he’d be less likely to end up the way he did. Maybe he could work at Caltech and hang out in Hollywood.
Oh, how I love Freddie Mercury! How I would have loved seeing Queen perform.
Without a second thought, Tesla. I’d set him loose at Carnegie Mellon University and let the wonderworking ensue.
Lovecraft would be my choice, as well!
Shakespeare, I’d love talking to him about his work for hours, also Julius Caesar, Leonardo Da Vinci,Napoleon and Machiavelli.
And he’d point out that he was never a god, & when he wrote them they were not interpretations, but decisions, & you ought to be able to write your laws for your own age like he did instead of “interpreting” his like a bunch of scribes & pharisees–& if you can’t agree on what the fool thing means, why are you still hanging onto it?
If I can get two, oh, I know it’s a small thing, but Nat Turner & Frederick Douglass. Get them together, give them some books on theory of war, & show them exactly how Reconstruction ended. Then send them back to try & change history.
Yeah, more slaughter of women and children led by a strangely dispassionate messianic figure would have done wonders for ending slavery. (Regarding Turner obviously, not Douglass.)
Anne Frank. And give her a penthouse apartment to live in while she’s here.
I would like to bring Mark Twain to the 21st century.
I don’t want any science fiction writers. How can I explain that we went to the Moon and didn’t bother to go back?
George Orwell. I would like to get his reactions to everything that happened in the world after his death, including the decolonization of the British Empire’s holdings, the Cold War, the Vietnam War, the fall of the Soviet Union accompanied by widespread revulsion for even democratic socialism, the rise of Jihadism, and the Information Age. And the tussling over his own legacy between LWs and RWs. I would also like to spend a month showing him around America, which he never got a chance to visit. In his writings there was both admiration and revulsion for American culture, but always fascination.
As for his having to be dead again at the end of the month – well, Orwell was always the kind of man who can accept it stoically when life sucks.