EMS Summit GTX Gaiters
Price Paid: ~$40 - $60
I've owned two pairs of these for a few years now, a large for mountaineering boots and a medium for hiking boots. The quality, in my opinion, is excellent. They are durable, stay upright, and fit closely to your legs and boots.
A nice feature is the top strap adjustment. The strap loops back on itself, and the tension is set around the back side of the gaiter, meaning you don't have to thread a strap through a buckle every time you put them on (This is a nice feature when crawling out of a tent in below freezing weather).
Once adjusted, they don't have to be touched again, since minor adjustments can be made using the velcro overlap. This also makes putting them on or off, or making adjustments on the trail rapid and painless. (When I first bought these only a few had this feature, but that may have changed by now.)
The Gortex is a nice bonus, but they'll still make your legs sweat if it's warm or your really humping it up a slope. I tend to use these in the colder months, and have never had an issue with snow or anything else making it's way inside them.
The price is better than or comparable to the big names, and being an EMS brand, you can usually get a good deal during one of their numerous sales.
Where to Buy
We found the EMS Summit GTX Gaiters at 1 outdoor retailer: