HAH!
Fools!
I would take an expresso machine.
I would rule the house parties and be popular.
You don’t make friends with an Apache Helicopter…
Oh, and I would take a self-replenishing huge-ass first aid kit.
Amateurs! You people are all overlooking the obvious…
A giant waterslide!
or a 18"DHIBJD. Either way, something that’s lots of fun to slide down
A toothbrush.
I’m in Florida, so it would have to be a machine that makes mosquito netting. Or a gun making machine to give the Native Americans superior fire power to keep the invaders out.
I’m in an urban area of New England. Hmmm. I could bring a computerized loom and get a 10 year jump on the textile industry, only making it much more productive and easier on the labor force. That would be wicked thoughtful of me.
Yep. I'd be stringing wires from the lightning rod on the old clock tower and revving up the Delorean.
But failing that, I’d have laptop with a stack of DVDs containing every scanned newspaper from the period, patent records for the next 200 years, and containing books detailing in exquisite detail how to replicate every bit of technology, medical or electronics. Also, every bit of literature, in case I need to make some money by beating Dickens to the punch And some kick-ass games, because the nights are long and dull in 1800 New England. (They’re also cold, so one of those hot Pentium/G4 laptops would come in handy as lapwarmers as well.)
I was going to say a heart defribillator, but the state of medicine in 1800 was such that it probably would take for-bloody-ever to get to a hospital from here in the lesser armpit of Virginia. That’s my main consideration here; a fridge does me no good at all in the wilderness, since I’ll probably freeze to death before I can get anywhere of use.
I’m going to extrapolate out and say that the endless energy supply also means an endless supply of properly-attached/filled tires, and go with a souped-up motorcycle. Thing is that anything else, while it might be useful from an informational standpoint, does me absolutely no good in a place that was barely settled in 1800.
Beat me to it 
I gotta go with Bob55.
Since the aircraft carrier would end up on land (since you’re on land right now right?) I’d have to join in with the helicopter crew.
That, and an instruction manual titled: My first Apache Longbow helicopter; a beginners guide.
You guys would crash that helicopter in short order.
It would make for a neat archeoligical dig in another two hundred years though.
Digger: Looks like I found an Apache in this here mound.
Co-digger: That’s nothin’, we find them remains all over the place.
Digger: Apache Helicopter…
Maybe your co-digger knew exactly what you were talking about. Judging by the number of people in this thread that plan to take an Apache helicopter back to 1800 (and then crash it), maybe he really has found those remains all over the place.
A good, simple, sturdy utility tractor. Nothing fancy, something in the 40-90 horsepower range. Since the OP specifies I can’t take a collection of machines, I’ll take plans for a simple plow and generator that can run off the tractor’s PTO.
My agricultural productivity will be so high that I can easily become the leading farmer in the Mississippi valley, which will allow me to become a prominent landowner, which will lead to my being elected the first governor of Missouri and later U.S. Senator. Then on to the White House where I will resolve the slavery issue and avert the Civil War.
Having achieved personal wealth and a stable democracy, I’ll retire to my estate where my later inventions will include the “trophy wife.”
[SUB]Man, I can’t believe I’m the first to say this…[/SUB]
A 1920s-style Death Ray!
And with it, I’d conquer the world.
An Abrams tank.
Easier to learn to operate than a helicopter.
The unlimited power it generates could fairly easily be converted to useful power outside the actual tank.
Unlimited spare parts = unlimited ammo.
You would have no trouble providing for yourself anywhere in the world by simply taking what you wanted or hiring yourself out as a mercenary/sherrif/assasin/etc. Think about how different the Civil War would have been with such a vehicle!
The biggest problem would be keeping people from taking it away from you and finding/training a good crew you could trust.
I changed my mind.
When you get your item and go back, you will appear at your same location? This means your home, where you currently live?
I’m only a hundred yards or so from the Merrimac River. Newburyport, my hometown, was the third largest country in the US back then. As long as I could line my pockets with enough gold to hire some laborers, I would bring back a boat. Pay some locals to drag it into the river for me and I’m in business.
With an Aegis cruiser, you would clean up as a privateer. Also, even a Coast Guard Cutter could easily defeat the strongest ships around then.
A good machining mill. It needn’t even have to be a CNC mill.
With that, I can (eventually) either make any of the other items mentioned, or make the tools that will make them. Or make the tools that will make the tools that will make them. And so on…
Industrial revolution, here I come!
A seaplane. You could make mucho bucks delivering mail, carrying passengers, etc. Hell, I could give Lewis and Clark a ride back home! Since you could land on water you wouldn’t need to worry about landing strips.
A Miele Novotronic washing machine.
One of those laser pointers, 'cause man, my cats love those!
Or a 1920’s Style Apache Helicopter.