A 1897 bible.
Second is a 1910 copy of one of the originial wizard of oz books.
Rock samples. Lots of 'em, various ages, various parts of the world.
Then: American envelopes from the 1880s, complete with stamps.
Then: more stamps, of various countries, late 19th century. Books (a pocket lexicon from the 1890s).
The fabric of the building. From the architecture I’me guessing that it was built around 1840-50.
Yeah, if we’re talking about non-man-made items I’ve got some fossils that are in the hundreds of millions of year.
But I’d say it’s best to limit it to man-made items just for sanity’s sake.
In that case…
Some pre-Roman coins (c. 300BC)
or
An oil lamp from BC times (exact date unknown)
My digital clock. The thing was around before I was born, and it’s still ticking today. (And I’ve thrown it across the room countless times; it just won’t die.)
Oh, did you mean antiques? Er…two lithographs I found at an antique shop, and the wallpaper in the diningroom of my apartment. So old it’s backed with cheesecloth. (And the runner on the stairs has to be pretty old; in the summer the adhesive smells like maple syrup.)
I have a history of Ireland that has no copyright date in it, but has a handwritten note by one of its owners in the front of the book which puts it around 1880 or so. The latest date I can find in any of the text is from the 1860s.
Right here on my desk: picture of my grandmother and two of her children circa 1902.
Oh yeah, my bedroom set dates from at least the 1920s, if not earlier.
A Hoyle’s book on card games, 1789.
My house itself was built in 1760.
Coins and bracelets from 1500 BC. Not sure what civilization they’re from. Second oldest is a rocking chair made around the time of the Civil War.
Shark teeth that are fossils. We also have 2 small vases that are stamped “Made in Occupied Japan”.
Coins back to the 1920’s. We are very modern.
The house itself, built in 1928.
After that, I’d have to say…my husband. 
Native American artifacts. Arrowheads and other stone items, that, according to experts, are thousands of years old.
A couple of really old books that my grandmother bought as collectables. I don’t know what they are, or exactly whence they came, and I haven’t looked into it yet.
Some coins from the early 1800’s.
A cavalry officer’s sword from the American Civil War.
Me.
Meteorite samples, 4.6 Billion years old.
Trace amounts of Hydrogen and Helium4 - 15 -20 billion years old.
I have some old ERB books that Captain John Carter of Virginia might find interesting, c. early 1900’s.
Many old photographic items, oldest from 1917, most from 1930’s thru 50’s.
Stereo speakers from the 70’s.
Paisley ties from the 80’s.
I have a TRS-80.
My Remington Monarch typewriter (early 50s, I believe.)
Ditto on the pre-roman coins.
We haven’t settled enough to collect any neat stuff, but I have a copy of Shakespearean tradgedies from WWII. It has advertisements for war bonds in the back, plus letters from soldiers about how the book meets the mailing requirements to be shipped to the front, and it sure makes them feel better to have something to read.
I also have an antique cast iron sewing machine, but I have no idea how old it is. I’d guess early 1900s, and it still works pretty well. When I find the owner’s manual (we just moved) I will look for a copyright date.