I played through all of GW and achieved almost all my titles with my ranger. I really like being able to pull enemies and direct the fight with her.
What I like about GW though is the fact that you need certain roles in the team. I was never a great monk but the challenges of keeping the team healed were fun. I played with a friend who felt that as warrior his job was to run into the fight and mine as monk was to keep him alive whatever he did - it was amazing training.
Playing as warrior meant making tactical decisions which was also a steep learning curve for me.
I wasn't so experienced as necro and rit but they were fun too.