What GPS works for you will really depend on how you intend to use it. I use a Garmin Venture Cx. It's basic but does exactly what I need it to do. I rarely use it to navigate, it would be kind of tough to truly navigate with it because the screen is so small. I mostly use it to track where I've been. Generally it gets turned on and then I throw it in my back pack, then when I get home I download the route and all the info about my trip. Occasionally I will mark a turn I want to take so I can make sure I won't miss it.
If you plan to navigate with it, I'd suggest one of the ones with a bit larger screen than the handheld Garmins, unless your navigation is while you are hiking, then they are great. Like I said, it really depends on what your intended use is. I may eventually get one that's a bit larger like a zumo or nuvi or similar so that I can strap it to my handlebars and actually be able to use it, but it's not a priority right now.