I'd like to underline several of these:
In many units, the Gerber multi-tool has replaced the bayonet. The multi-tool has been popular with troops for years. About the same size as a bayonet, the multi-tool includes needle nose pliers, a wire cutter, a drop point knife blade, screwdrivers, a can opener, a bottle opener, among other things. The troops love this stuff.
Either a Gerber or a Leatherman, goes over big-time. I've yet to be in a unit within the last four years, where every other troop had one or the other. They're just too damn useful.
Hand held laser pointers have been popular for troops expecting to get ambushed. The laser pointer makes it easier to show where everyone should shoot. Sounds crude, but it works, and has worked many times. It also proved popular for raids as well.
These lil' buggers are cheap - I've seen them as low as $8, and made as part of a key chain - and dead useful in field or garrison jobs.
Canteens are considered so 20th century. Today's trooper wants a camel-back hydration system (a bladder of water carried on your backpack, with a tube that allows you to sip water as you need it without having to use your hands to get the canteen out.)
Two reasons why I'd opt out on these. One, they're still expensive - $40 and up, last I checked. Two, Camelbacks are issue items for almost every unit going to The Sandbox.
The army issued GPS receiver (the PLGR) is old and put to shame by newer GPS equipment. The 82nd Airborne division went out and bought Rhino GPS units for all the troops. This unit was lighter, smaller, got more time out of the batteries, and picked up the GPS signals faster than PLGR. Many troops had already bought the Rhino (spending about $200 to do so), and similar models. But many troops are stuck with the PLGR and would appreciate something better.
Any avid sports guy might have a Rhino, or a Garmin, or a Magellan. My Guard company made a local purchase on three; blew some training money, but our surveillance guys needed them. I echo the commentary on the PLGR: if you have nothing, then they're great. If you can get hold of better, do so.
Only thing I could ever add to this wish list: A cheap-o digital camera! One that you can quickly upload the pics to a laptop - and laptops are becoming the equipment of choice in almost every unit - purge the camera, and shoot some more. I've got one we found for $20, and my new laptop will be mated up to it soon.