Tim, what do you want it to do for you?
Seriously, all of the GPS units sold are reliable. The thing is, do you want to use it on the boat only or for biking, camping, in the car? Can you or do you navigate with charts: if so, the basic model suggested by Richard is fine (we have an eight year old Magellan 300 with only numbers, no chart display AT ALL). Do you want or need a chart-plotter or simpler built in database of buoys, then the G76 or G76 Map is what you'll want. Do you want to use the hosue battery, or rely on AAs? We just don't know, so all we can tell you is how much we each like ours, which doesn't really answer your question. I recommend you read West Marine's catalog or Advisors online about GPS units and figure out what you need and what you can or will afford, first. Then, once you've narrowed it down, I'll bet there's lotsa folks who'll help you find a great deal on the purchase! I love my Magellan, because it has a simple GO TO button. The Garmins all require you to scroll through a menu in three steps to get there. Can you learn how to use it, you betcha. The downside, to me, of my friend's Garmin 76, which has the preprogrammed buoys, is that the screen is too small to see anything worthwhile, and when you zoom in, the preprogrammed stuff obliterates your own data. That's the advantage of the G72, less screen clutter. I think you should also go to a store and try some out. So much of this stuff is personal preference.