A huge tract of forested timberland butted up to a lake. I’d create an experimental forest of my own design.
Clean underwear.
(hey, he startled me when he jumped out)
ETA: OK, ferreals? One of those big foot-long Milky Way bars. Really. For a couple reasons: shock value to match the shock he was looking for, and I don’t think I could enjoy something lavish if it were given on a whim. As a gift to ME for just being ME? Sure. But random windfall? Nah.
Lots of land in Oregon, to operate a huge organic farm.
For some reason, that reminds me of an old sketch from “Fridays” - anyone remember Ganja Man? He did a bit where he was “Ganja Claus,” pulling various doobies out of his bag for punchline names. Finally he pulls out this two-foot monster.
“Now whooo could dis be fo’?” (Peers intently at label. Slowly grins about six feet wide.) “Well, waddya know. It’s for ME!”
Well I DO live in Colorado…
Can I change my answer?
http://www.hersheysstore.com/product/worlds-largest-york-peppermint-patties
The East Broad Top Railroad, plus a million or so to put it back in operation.
I’ll take the Yankees please. Thank you Mr. Billionaire.
If I had a Faberge egg I would feel supremely fancy. Oh, but which one would impress the baroness the most?
If I can’t decide, and I guess I haven’t so far, I might go for that silver swan with the clockwork parts. You know the one I mean.
…and then disband them. Just because you can. 
I’m gonna go with a pallet load of cash, like the one in Breaking Bad. This is not just a load of money, but an art installation at MOMA in NYC or the Art Institute in Chicago. The purpose is to remind the public how much money can be made by producing a high quality product at a competitive price.
The dream house my husband and I have been talking about for years. Big enough to have a music studio for him and a crafting room for me with a home theater room as well. I suppose we ought to ask for the gym room and 6 bedrooms with a loft for all the grandkids we are expecting (eventually.) It should be on about 5 acres. Enough that my husband doesn’t feel shorted, but not so big it’s overwhelming to take care of. It should be slightly outside of town, but not so far it takes more than 10 minutes to get to a grocery store.
The Amazon rain forest, to hold as a wildlife sanctuary.
I’d like American Pharoah, please.
It’s a fun question – thanks for posting it!
In '81 (maybe late '80) I was living on the outskirts of San Antonio, Texas and, believe it or not, was beamed straight out of my bed one night and onto a UFO craft…!
And so, I’d VERY MUCH like to be given said craft, or one just like it (with lessons on how to fly it, of course).
P.S. Like Larry King used to say on his nightly radio program back in the day, “There is no accounting for taste.” (No offence, but that lady in the painting you’d dearly love to have almost makes the new Bruce Jenner seem very desirable by contrast.)
I’d like a ticket to fly on one of the Virgin Galactic flights into orbit once those get started.
Choices, choices! 
I think it would have to be an aircraft. If the gift comes with a trust fund for maintenance, insurance, etc, I’ll have a Spitfire, please. I would have asked for an Arado AR-234, but there’s only one of those left and it’s in the Smithsonian, and it needs RATOs, so there’d need to be a supply of those as well. If maintenance funds are not available, I’ll go for a PBY Catalina.
[del]Kuala Lumpur[/del] France
Seriously though, there’s not a lot of “stuff” I really want, especially not big stuff. I suppose my dream home would be the closest thing at the moment, but I’m not sure I could articulate what my dream home looks like without a lot of additional thought.
A seat on a DSE-Alpha expedition.
Honestly, it’s not even really that important if I wouldn’t make it back alive.
A private beach party in either the Caribbean or Australia with music provided by Jimmy Buffett.
Fellow Dopers are invited as well. 