GPS systems are notoriously fussy. Unless you're willing to shell out for a multi-receiver, sub-centimeter rig from a professional-grade supplier like Trimble or Ashtech ProMark, you're likely to get results that vary in accuracy from one session to another. Calling one phone brand or another "crap" is silly, since you'll find individual handsets from Samsung, iPhone, BlackBerry, etc. that perform well or not so well (and often performance is location-specific). An interesting article about GPS errors can be found here:
Introduction to GPS Chapter 6
Of all the GPS-enabled phones I've owned, my old BlackBerry Tour was the most reliable, and my current Charge is the least reliable. But the Fascinate I had previously was superb.
As a side note, a buddy of mine purchased a mobile (hand-held) GPS marketed by Garmin for aircraft use. Spent about a grand for it. It was typically at least 50 meters inaccurate regardless of where we were - he missed so many turns while using it in the car he quit using it. And this thing didn't make phone calls, play Angry Birds, or take pictures.