Emphasis on the as you. Say you pick the Marvel Universe - you don’t get superpowers. Middle-Earth, no sword-fighting skills. Star Trek, you have no clue as to how any of these gadgets work. You just appear in the area of that universe of your choice with the clothes you stand up in.
I’d still pick Middle Earth, specifically the Shire: My life-style is pretty hobbity; I’m short; and when I was a teaching assistant the students said I was “earthy”. I’ll wear my “Frodo Lives” tshirt.
Star Trek of the 24th Century. Except for someone trying to blow it up every other year, Earth is a paradise with what looks to be a heavily socialist government so I could spend all my time doing whatever I want.
Battlestar Galactica. Those dumb-asses may have FTL drives but based on the level of technical expertise I’ve seen on the show, it’s run by a little metal valve thingie and when it goes off-line you have to bang it with a hammer.
Can’t tell a Cylon from a human, gimme a damn microscope, fool. I’d run that place.
Default answer: 24th century Star Trek Earth. With the possible disadvantage that, if my origins were found out, I might not end up in a nuthouse, but they might believe what happened to me and try to send me back home.
The 1632 universe might be interesting…till I ran out of medication. Or I got drafted and died of typhus in a siege. Or ended up going down in (altered) history as the as the guy who first tried to use hydrogen airships for tactical air support (with somewhat limited success).