I seem to have lost my beloved Garmin eTrex HCx, which I use for geotagging, as well as driving directions and other useful things. I love geotagging so much that I'm going to have to replace it. I've got a Garmin fitness watch with a GPS (the Forerunner 305) and I can extract .gpx files from it in a pinch, so I'm not totally out of luck. But I see a new Dakota 20 in my future soon.
Keep in mind that if you're going to do geotagging with photos after the fact, you need a GPX (or similar) file. The easiest way to get a GPX file that I know of is to use a Garmin GPS with a microSD card. There's a mostly-hidden feature you can enable that just writes .gpx files to the microSD card whenever the unit is on. These files are invisible to the unit's UI and aren't related to the "path" memory, and can't be erased via the UI. The unit just silently creates a track of everywhere it goes, and then you can copy this file to your computer later.
The only downsides seem to be cost and size/weight. The cost is steep: about $300 for the unit. I've seen GPS units way cheaper than this but it all boils down to convenience here. The constant-logging to the GPX file is a really esoteric piece of functionality that not many people are probably interested in. It's hard to shop around for that feature since most people don't even know that feature exists. Garmin doesn't even advertize that feature of their own product!
As for size/weight, I'm ambivalent about this point. Part of me thinks the units is just small enough and part of me is still annoyed that I have to add 6 more ounces and fill one more pocket. Part of the weight and size comes from the fact that it uses 2 AA batteries and I think that's a Really Good Thing. As I've said before, I love standards like AA batteries. Sure, portable electronic devices can be made smaller by using integrated, proprietary battery systems. (Look at Apple's laptops, which are getting smaller and smaller, partially due to the decision to drop replaceable batteries.)
But I really like AA batteries because in a pinch you can find them anywhere. You can buy AA batteries in the middle of the jungle in Vietnam. (I know, I've been there.) I've stepped out of a wedding reception for 2 minutes to walk across the street and buy a pack of AA batteries at a liquor store before. For these reasons, I'm willing to accept the slightly larger weight and form factor of the Garmin GPS, since I know I can grab spare power anywhere.
In conclusion, I'll probably be picking up a new GPS soon. If so, I'll let you know how it works out.