Don’t mention the word “Pern” in my presence, you mendicant!
Or in the presence of anybody else who has any sense of good taste in science fiction, either! :mad:
I don’t think the Harry Potter universe would be a good choice. Under the rules I proposed, chances that going there would result in wizard powers and/or entry to Hogworts are slim to none. Also, talking about what you learned from the books would get you memory charmed really fast. For the average Joe, you may as well be here.
On the other hand, in a comic book universe, all you need is sufficient motivation and a costume to become a superhero. And once you are a superhero, you practically can’t die (or at least die permently). Being an innocent bystander, however, would not be good thing.
I like the “take over a sword and sorcery world with science” idea- explored in some depth by the Joel Rosenberg “Guardians of the Flame” books- highly recommended. Just make sure you choose the right sword and sorcery world- preferably a poorly written one, to give you more leeway in what you can do. I still think Conan with a sword would beat you with a .45.
Is all manner of natural light blocked out by solar collectors? Are food and drink replaced by protein supplements and vitamin-enriched water? Are the only forms of dress gray jumpsuit and light gray jumpsuit? Are people artifically kept from biological signs of aging until their death? Are the only plants and animals accessible by citizens in quarantined recreation zones? Are the most aesthetically pleasing buildings only half-covered with external machinery and billboards?
If so, sign me up!
I’m such a romantic…
It’s been my experience that that description fits the world we do live in quite nicely.
Adventure and mystery around every corner, new miracles of science each and every day, and a night sky filled with wonders.
Also, I expect that one day I’ll walk into the magic shop on Frankford and the owner will take me into the back and show me genuine flying carpets, dragon eggs, and talking animals.
I dunno, the problem is, then you become the Brilliant Science-y genius. Which could be fun or could get you burned at the stake, depending on the quasi-medieval society you land in.
And the genius of the OP (with my fantasy worlds) is, if you’ve ever read fantasy, you know it’s always the everyday, boring characters that have the epic adventures. With that in mind, I’ll move to those Realms and become a farm boy. Soon I’ll find out my father/mother was a great wizard/warrior and now I have to have epic adventures to save/conquer the world.
That is why I would first pose my self as a HERO (- outsiders with powerful weapons(like my firearms) make good heroes.) - by the cliche of rescuing the princess, and then marrying her to gain the throne. Then I can introduce the technology, and gradually take over the world - striking at the evil and corrupt kingdoms first, since in fantasy novels good typically wins.
For fun it would be Philip Jose Farmer’s World of Tiers. I’d hang out at the bottommost tier for the eternal youth, stunning looks, and mind-blowing sex, with the frequent jaunt to another tier for more adventure.
For intellect it would be in an Edenist colony in Peter Hamilton’s Night’s Dawn trilogy. Bitek is definitely my cup of tea.
For sheer adventure, shoot me over to Jack L. Chalker’s Well World. I’d give anything to meet up with Nathan Brazil and Mavra Chang, head out across the hexes and meet up with alien races and societies every few days.
I agree that if one acted like a Dungeons and Dragons character in real life you could definitely find adventure, and possibly riches - that if, until you were arrested.
Discworld. But only if I can be my namesake therein. 
Discworld - if I can be a Wizard (one z).
Otherwise how about the Gibson/Sterling Difference Engine 19th Century England - I’d be a damn good clacker. Interesting times and a meritocracy of sorts.
Dan Simmons’ Hegemony, before the Fall. I want a Farcaster House (For those unfamiliar with Hyperion, that’s a “structure” with interstellar teleporters in every doorway, so that every room is on a different planet.
Springfield.
Or failing that, I’d like to be a Lancre witch.
I’d want the Riverworld, but only if I could be a crewman on the Not For Hire.
Or Chalker’s Well World universe, but only if I could have access to and control over Obie.
But both of those stipulations violate the spirit of the OP, so instead I’ll say:
The 30th century as imagined by Paul Levitz in the Legion of Super-Heroes.
Or, Alan Dean Foster’s Humanx Commonwealth.
Or, Dinotopia.
Bosda, sounds like you and I are the only ones staying out of the sci-fi/fantast/etc. realm.
I’ve never liked that stuff much, except for Star Trek when I was younger and Star Wars when i was a preteen and it was the coolest thing. But, while I don’t remember Pogo, “Peanuts” world would be so cool! There are adults, of course, we just don’t see them, and I could keep working as a Sunday School teacher and sutff. Very relaxing place. And, most importantly, the dogs like Snoopy can do some amazing things, and he could take for a ride in his doghouse if I became good friends w/the Browns. So, there’s a little adventure there, mixed witht he peaceful, relaxed pace I like best.
Roger Zelazny’s Amber.
Amber being the Center of all Things and all other worlds are Shadows of it, I can get all your worlds any time. 
I would like to Emigrate to the Babylon 5 universe, pretty darn amazing
I’d really like to live in the universe of Robert Anton Wilson’s Illuminatus trilogy! Where history is a sick prank and you are the victim! Where every conspiracy theory you ever heard of is literally true! Where evil cabals of human megalomaniacs share power with incomprehensible demonic beings from another dimension! Where . . . what’s that? You . . . you mean we’re already . . . oh, well. Fnord.
I’d go with Brave New World, despite being a dystopia it doesn’t seem bad. Its the most utopian dystopia I think.
Although being one of the low castes wouldn’t be fun I suppose.
I’ll echo Tanaqui and go with the Culture; I’d just avoid joining Special Circumstances. Well, maybe after I get bored in a few thousand years…
The DC universe, but only if I can contact the right people. Simply -knowing- a lot of what the readers know could make one very useful, as well as very well connected. (No, I’m not selling out the heroes. Sheesh.)
The world of Theah from the RPG ‘7th sea’, for similar reasons. Plus, gotta love a world where swashbuckling is de regeur (sp?)