I gave GW a try last year when I became bored with WoW. I did not really care for the game all that much and got rid of it. Things I did not like:
1) Everytime you leave a town you enter your own instance (private world). This means that you will never come across any other players, only NPC's. Makes the entire game seem very lonely at times.
2) Some of the areas I wanted my character to walk to were inaccessible. For example, when I wanted to go down the side of a hill, I had to go around it to get to the bottom, rather than just jump down or walk down the slope itself. This made for a very unrealistic experience.
I thought the graphics were decent but not as great as some people had made them out to be. The questing was ok but again, nothing special.
I was really excited about this game when it first came out but was already playing World of Warcraft so I did not try it until last year. Was very disappointed.