[Spoiler Free Review] An MMO built off of fixing the mistakes that other MMO's make.
First of all, the game isnt one massive fight for loot. After every monster is killed, any player that has a hand in killing them gets their own loot - this means that boss spawns are placed in chat so that many, many players can teleport to them and participate, which turns a normal boss fight into an all out war, as the boss scales with the players that are there - this makes for a very cool experience, as it really shows off the Guild Wars community.
These events are all clearly shown on your map, and when shown, you can join them - if you're alone or in a party, if the fight has started or not. What this means is that a fight may start with a small group of a dozen players, but suddenly there are 40-50 players all hacking away at the same enemy just to get that sweet, sweet loot.
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And finally, the quest system in Guild Wars 2 is the best I have ever seen. Each area of the map is dotted with quests, denoted by a gold heart. Rather than picking up a quest, doing it, and returning to the questgiver however, you walk into an area where the heart governs, and it will give you the quest at the top right. You can perform all or part (or none) of this quest and leave - if you partially complete it you can come back later and do the rest, and if you fully complete it you are sent the reward - no need to hassle with walking back to the vendor and turning it in. This system is so much better to use as it allows you to quickly gain XP as you travel from place to place.
In conclusion, Guild Wars 2 is an amazing game that can only go up from here. Whilst it may have some problems (the main one bieng WvW) it delivers an amazing story mixed with gameplay that takes the things you hated about MMOs and makes them fun again - definetley something anyone should pick up and play at least once. The game is made even better with friends, and since the cost doesn't matter until you decide to purchase expansions you don't need to worry about them saying "I would, but it's so expensive".
Guild Wars 2 is a game built off of the mistakes of other mmo's - more specifically, it's built off fixing those mistakes to improve the player exprerience - a task which it performs splendidly. The problems I've mentioned in this review are just a snippet of improvements Guild Wars 2 makes to it's game. If you haven't played it before, why not? It's right there.