GW2 takes the best pieces of the genre and leaves the rest.
This game is obviously a labor of love, and it shows. The environments and character models are beautiful and detailed, and it's a pleasure to explore. Dynamic events give a feeling that you're really helping and making a difference, and boss battles are an amazing experience.
Combat is fun and varied, as skills change based on weapon type you are holding, and picking up objects around you such as bombs and rocks give you new skills temporarily, which is a lot of fun. It also means you're never overloaded with a ridiculous shortcut bar of 30 icons like in some MMOs. Your level also scales to the area you are in, so you can still have fun with lower level friends.
PvP is fun, and brings back one of my favourite games from DAoC, which allows you to capture and defends forts. Everyone is the same level and has the same gear to pick from, so PvP becomes more about skill than grinding for gear, which is fantastic.
Crafting is also well designed, with the ability to take stuff in and out of storage in the crafting panel, and also a 'discovery' mode that allows you to combine ingredients to find new recipes.
There is still some room for improvement in GW2 though, and that's a good thing. For one, I'd like to see lip-syncing outside of cut-scenes, and a few more mechanics for social interaction (ie, being able to sit and have a drink with friends in the pub, the ability to play music, have a bar fight, etc.). I'm sure some of these things will be on the cards for a future patch.
If you're like me, and have been burned out on the MMO genre over recent years, pick up GW2 and have some fun. With no monthly fee it's a no-brainer really, and there's 100's of hours of gameplay in here for your money.