Guild Wars 2 is a very fun game. Well worth the box cost as it can provide a lot of hours of entertainment w/o ongoing fees.
Before anything you must understand Guild Wars 2 is a casual focused game inherently. There is also no raiding, endgame, gear or class trinity.
Isn't a matter of "better than WoW"- the question you are asking is kinda not good. Guild Wars 2 is different from WoW in a number of significant ways, however.
Would STRONGLY advise you educate yourself on the particulars of Guild Wars 2:
I won't say it's better then WoW because i feel like they can't be compared, but it's deffinetly worth the money you're paying. You get what you pay for and more. You don't pay for server access, nor do you pay for content patches so it's kinda a win-win situation.
Buy it, and see for yourself. I enjoy it a lot myself. Even if you do not like it, you will not have wasted more cash than you otherwise would on any other tripple A release. Also you can come back to the game any time you feel like in the future without any cost what so ever.
There are a ton of threads with information on the game in the forums, both stickied and non-stickied.
If you have specific questions that you can't find the answers to, feel free to ask them, but "Should I buy the game?" threads are kinda like "What class should I play?" threads, and aren't super productive.