For car navigation I tend to suggest Garmin. For aviation they are awesome, but they also have fairly little competition. Their hiking hardware is VERY capable, although I disagree with a few design choices like touchscreens and mini-usb ports, for durability reasons.
The only reason, besides that I own one, that I would recommend a PN-20/30/40 from DeLorme over ANY Garmin unit is the
map support. Other than the "t" series units, the Garmins do not come with topo maps in the box, adding extra cost. The PN-series come with 100k vector topos in the box. And, it is $30/yr for 24k USGS topos, aerial photography in both B&W or color, and NOAA nav charts. Yes, you can download free vector topo maps for the Garmin, but they are unsupported. Yes you can get nav charts, for serious $$$. I pay $30. A year. And right now the DeLormes are WAAAY down in price. My PN-40 was almost $150 more than I could get one for this year. However, Garmin's 24k map products are more up to date than the 24k raster USGS maps DeLorme offers. They are also a ton more expensive.
But, if I were into geocaching, I'd probably prefer Garmin due to the larger free software base. It all comes down to personal preference. For a person who ONLY hikes, no geocaching, and who does bushwhacking and impromtu hiking, I need the map support more than the geocaching software.
Now Magellan... I wouldn't touch that with a 10 foot pole. Never again. My Meridian Gold was a nightmare, enough said.
But... As I've said dozens of times... We can pontificate all we want, but the decision comes down to you and what you want, need, and can afford. We can tell you why we bought what we did, but not what YOU should buy.
My review of the PN-40 is at:
http://waterfallchasing.b...re-view-introduction.html