The game that takes the MMO genre forward...
Secondly, presenting my credentials - I played WOW up till last year from release, I've tried every major fantasy MMO since then (LOTRO, DDO, RIFT, AION) etc etc. And SWTOR, TSW.
Guild Wars 2 - take the genre forward. No questions asked.
It deals with a lot of the niggling MMO issues that older MMO's suffered from. ArenaNet have questioned all aspects of the accepted wisdom within an MMO and just changed the things that get in way for the fun. It's pragmatic without being cynical. (For instance - no mailboxes, mail comes straight to you - but a pigeon flies by - a lovely touch)
The replay-ability and scope is enormous - every event or quest is useful to everyone as soon as they reach that level and for ever after. You can adventure in the starting zone over and over.. and get gear for your level.
A lot have been made of the "dynamic events" too much in my opinion, they are a step forward from static quest givers, they are a moving target, but let's be honest they are a repetition. That's not a criticism, it's not a bad thing, it's just a fact. There is still room to do more - as the technology can handle the complexity.
And that's my final point - the room to do more, to advance in the MMO space is huge and exciting and GW2 is pointing the way.
Excellent effort.