Left: Arno skiing on the blue ice of the continent, near D-10.
Even though the weight allotment is limited, people take the oddest things with them on winterovers. During my first winterover, the plummer brought a sail and a mast and then proceeded to build a snow yatch out of steel tubes. It was so heavy that it never managed to move an inch and he was too afraid to try it when the wind was strong anyway.
Keep in mind that the weight allotments vary depending on your destination. You can sometimes cheat by putting some of your stuff in official work equipment ("no, that's not a vibrator, that's a... mixer for ice chemistry experiments!"). Also you won't want to take the same kind of things inland, on the shore or on temporary and uncomfotable field camps. Some stations don't care much about the weight limits. Others do.
Also keep in mind that personnal stuff must be sent some time ahead, up to 2 or 3 months, and the same way it shows up late when you get back home. So if you send your computer ahead, you won't have it for 6 months or so; plan ahead. Some stuff can be mailed to you during the summer but with no guarantees (I once barely received a camera lens replacement on the very last flight of the summer).
Your own computer with plenty of spares parts, in particular spare fans and spare hard drives. And about two backups: Antarctica is hell on hard drives (prefer SSD whenever possible). Accessories such as headphones, speakers, external SATA connector, USB/serial adapter for whatever strange equipment you may have to deal with on the field, all kind of cables and connectors, USB hub, ethernet switch...
At least two cameras: a big one and a small one which you can keep in your pocket at all time. A camera that can do tricks such as time-lapse is worth considering for stars and slow changing weather.
Your own thermal wear. Official issues work fine but are often heavy and may not be very comfortable, scratch, scratch... This applies to thin underlayers up to the full down suit if you can afford it.
Your own headlamp(s). In particular see if you can find any with a battery pack that stays in your pocket as the others don't last.
Anything that you really need such as eyeglasses (with spares) or medecine.
Books. But not too many unless you really expect to have nothing to do. There's usually so much work and booze that I've never been able to read more than a handful of books. If anything, Antarctica is not boring. And also there are plenty of books left over from previous years.
Right: Rubber stamp of the 1997 mission.
Personal rubber stamp with your name, the year and some funny (?) sketch of your job (stamp collectors will often send letters and ask for your postmark)
Flannel sheets which feel much warmer than the standard issues.
Slippers for indoors. Some stations provide them , but then they are all identical.
Ear plugs. You never know if your room will end up next to that of a guy with a 12h offset on your own schedule and a hammering fetish.
Anything that might cover your hobbies: if you like carving or building models, don't expect to find quality wood there! Magazines are nice as you can simply leave them in some common room. Well, 'White Power' may seem like an apt name for Antarctica, but still...
Same for sports. In all the stations you'll find a basic gym with weights, static bike, etc but if you like fencing or anything fancy you are on your own ! Among the tiny things I've brought: a quality jumping rope and a pair of shorts.
Backcountry skis seem like a good idea (at least they are lightweight to carry), but if you are in the center of the continent, it's so cold that they don't slide at all. And they work no better on the sea ice on the shore.
Probably a lot more fun if you can afford the extra weight: a snow bike. Don't forget spare parts.
PrOn. Nuff said.
Stuff to enjoy with others
Plenty of ideas, a sense of humor and a extra dose of patience.
A good list of jokes and practical jokes.
A hard drive crammed to the tits with classic movies, recent movies, humorous videos, lots of music, music videos. Software to convert between formats.
Good wine if you can ensure that it won't freeze during transportation, which is not a given. Writing [Do not freeze] on the case is sure to be ignored. Otherwise liquors, cigars, quality dark chocolate, anything to share and enjoy with others...
A homebrew beer-making kit of the kind with two plastic 30L buckets and several cans of malt concentrate. Easy to make and won't suffer during transportation. Reuse champagne/beer bottles from the trash heap. Don't forget extra caps or mechanical taps.
Sprout seeds and grow-kit so you can have something enjoyably fresh and green to eat regularly, even in minute quantities.
A bunch of frisbees, boomerangs, balloons, pétanque to play outside when it's not too cold. Some people play golf with colored balls but they keep losing them anyway if the snow is any soft.
And more specifically for the midwinter
Musical instruments. Even if you play like a goose in a concrete mixer.
Horror/comic makeup, wigs, clown stuff
Punk-strength hair gel, oxidizer to change hair color
Woman makeup, clothing and shoes (especially if you are a man !). Who knows when there's gonna be a Miss Antarctica contest...