If you want a no-frills waterproof, shockproof GPS that tells you distances without a bunch of bells and whistles, I like my GolfLogix-8. You can get them cheap on ebay and I got mine with a years subscription included. I haven't renewed and can still download courses and put them on the unit. Pretty accurate when comparing to my rangefinder. It's a two year old model, and I don't know if they have come out with a new version.
If you want hole layouts, cursors, colors etc. then this probably isn't for you.
If you have a smartphone with GPS already such as iPhone, there are quite a few apps out there doing the same job as the stand alone unit. I have use one for two years before I got a laser this summer.