I'm not sure what you guys like, but you do play FFXI... I'd say rent, and if it clicks with you do what you feel is natural. It's open world like GTA, you can do random things, or stick with the main story and get randomly interrupted or sidetracked along the way. The sidetracks for me have been good sidetracks. There are uber armors, and hidden things like a UFO crash site (you get some alien weapon. I haven't found it yet but I will look for it now I guess).
The game is pure adventure, and I think it's better than the FF games that I have played. Yesterday I was talking with a computer and I convinced it to destroy itself lol (gogo chr actually being useful). Also I was given a the fate of the world is in your hands choice. Either kill my minority friends which have more bad people in their group than good, or watch as the world is burned and die out with hope of another way to save us all. It feels like my choices are effecting everything, and usually it's not a clear and cut choice.
Everything you do seems to effect things. The way people see you, the options you have, the friends you make. I still dont have that dog and I feel I'm near the end of the game. I never blew up megaton (the city), and I haven't disarmed the bomb. I'm doing things my own way it seem. The game is awesome, and I would definitely play it again, maybe be evil, be a scientist type, a melee heavy dude, or whatever. You can't be everything, the game only lets you exp up to level 20 or 30. There are a ton of perks, skills, and abilities. You can only pick so many and it allows a great diversity of character builds. Did I mention the game is awesome?
So far the flashiest loot I have found was a Tesla Power armor.
http://www.youtube.com/watch?v=4iMOrXxyCsMOh also, don't go into this game treating it as a FPS. The VATs system (the thing where you stop the action and choose where to hit opponents) is very useful, and needed in most cases. I don't know how it controls with a mouse and keyboard, but the sensitivity with a control is a bit jumpy. I don't like trying to play it like a main FPS game. Think about how oblivion is with spells that shoot at enemies. That's pretty much how guns are with Fallout 3. To explain it, it's hard to be accurate. Also the game determines if you hit or miss anyway based on your skills and equipment (like a war hitting stuff in ffxi). This is a rpg in first person (or 3rd if you pick the crappy 3rd person camera).