My sandals. I swear I lose my sandals. Every spring I buy a new pair of those sport-type Nike sandals. Come fall I put them away for the winter and promise myself I won’t forget where they are.
I’m going Saturday to buy this year’s pair. :smack:
I give up on sunglasses, my eyes can just go rot.
In less than a year I’ve lost two pairs of Maui Jims and one of Polaroids, for a total of around $AU700. $20 pairs however hang around for years.
I have six tape measures between my workbench and my front counter. I know where two of them are right now. Those will disappear and then I’ll have to go on a roundup yet again. :smack: I try to always keep one on the right front pocket of my jeans so I have one when I need one.
My 7/16 wrench and the 9volt battery/cable tester thingy I use to tone out cable. I don’t always drive back to the house to get them since there is a good chance I’m going back that way the next day or two. You’d think by now I’d just add them to my mental checklist of stuff when I pack up to leave.
Scissors. I have a zillion pairs of scissors–big scissors, little scissors, sharp scissors, dull scissors, Fiskars and generic–and sometimes I can’t find any. Somewhere, there’s a house where scissors just appear randomly. Those are my scissors.
The remote. But it’s usually stuck between the couch cushions.
My pants. You have no idea how often I have a good reason to say, “I have misplaced my pants.”
My sanity.
I lose everything when I clean. When things get “put away”, I can never find them. I have what they call organized clutter.
Also, I inherited my mom’s losing the watch thing. I routinely lose it for a week or so at the time, usually it is in a kitchen cabinet, purse, or coat pocket.
I am wearing it right now, though. 
Yet another vote for nail clippers. I’ve also moved on to misplacing nail scissors.
Cell phone charger, lighter, p.o. box key (lost at the moment, usually for a week or two at a time then found for a few months. A real pain… I have to go to the desk and look like an idiot… “No… I still don’t know where I put it.”)
Scissors. I think there must be an oversized magnet under the floor of my son’s room because all the scissors seem to end up there.
Many of the above – scissors, tape measures, nail clippers, lip balm – but the one that makes me utterly crazy is two videotapes, one of my own appearance on Jeopardy ten years ago and the other of my quasi-son’s appearance on The Price Is Right. I lost them for at least two years, in spite of hunting diligently. (He keeps losing the copies of the tape I’ve sent him over the years, hence my holding onto it; I know I’ve sent him at least five.) I distinctly remember finding them in a particular cupboard a few months ago and putting them away somewhere else “for safekeeping.” Sigh.
At home, combs. Seems like I have to buy a new comb every two or three weeks. At work, we all can never keep track of the packing tape dispenser. It is never where you last put it.
Tweezers! Grrr. I just lost a pair of Tweezerman tweezers. I lost them a lot when I first got them, but recently I had been so good about putting them back that I’m thinking that they must have fallen from the medicine cabinet into the garbage or something. 
I have some crappy pairs of tweezers somewhere, but they are not the same!
Scissors here, too. That is, scissors-for-paper – scissors-for-fabric never leave the sewing room. I’ve finally bought enough pairs of scissors-for-paper that I have a reasonable chance of finding a pair within the first two or three places I look.
(“Reasonable chance” will remain undefined, of course!)
As I remarked one morning last week, had I been Native American, my name surely would have been named “Woman Who Misplaces Shoes.”
I can’t seem to find an emery board when I need one. My cats like to bat them around, and unless I hide them way at the back of a drawer, they always get pawed out and mauled or shoved under the bed. Ever since a couple of the cats learned how to open drawers, it has been open season on emery boards. Hair scrunchies, too. My possessions are not my own. They are all subject to becoming cat toys.
Wristwatches and sunglasses.
No expensive sunglasses for me, most I’ll spend is 15 bucks, and prefer to spend around 10.
Wristwatches? Most I’ll spend is 15-25 bucks, usually find some pretty stylish cheap ones for 15ish at Target.
Nail clippers, scissors, lip balm, tweezers, pens, embroidery needles. My PDA, on occasion - talk about stress-inducing. Typically I forget it at work on a Friday and have to fret all weekend about if that’s where I left it and whether or not it’ll be stolen before I get back.
For pens at work, sometimes it’s because the doctors steal them. At my last job, also in a hospital, we were going through pens at a fast pace until we bought one of those bank-style chained-down pens and put it by the phone message area for the doctors. Suddenly we had pens remain on our desks more reliably. I’ve considered having personalized pens printed up with “This is not your pen” on them.
My husband lost sunglasses frequently until he bought his first expensive pair (Oakleys). After that, he was very motivated to keep track of them. His second pair is a better pair of Oakleys, but he still has the first pair as a backup in the car, in case he leaves his good pair at home accidentally.