I think that a combination of both a 3rd and 1st person view would be the best choice. That way it would be easier to manoeuver your character when in 3rd person view while it would be alot easier to aim and fire your weapon when using the 1st person view. The 1st person view would add alot to the sence of that it really "is you".
And if the game would allow the player to choose between both the 1st and 3rd person view it would appeal to a broader audience as some like 3rd person view while other prefer 1st person view.
