I don't really have a particular preference here, other then that it more or less depends on what kind of game it is.
A pure shooter, like a Crysis, Farcry, BF, CoD, etc, then 1st person is in my opinion prefered, although 3rd person view can work ok as well (depending on variations of the game it's self).
A game like Mass Effect is one that I feel can work in both 1st person or 3rd person (although, ME never had a 1st person view, except for with sniper rifles when you aim with them), and I do not in any way feel they made a bad choice going with a 3rd person view... I mean it would be compleatly pointless to have a system where your character looks different based on the armor used, if it was a 1st person only game. The same goes for Fallout 3 and New Vegas... those are games where a 3rd person view is partly validated by the fact that your characters look can change, I personaly mostly played in 1st person, but I highly appretiated the fact there was a 3rd person option.
In games like Fallout 1+2+T, Dragon Age, Shadorun Returns, the upcoming Wasteland 2, or the more obscure games generally known as "Brigade E5/E6/E7/E8", I prefer if it is possible to have a isometric or top-down view (with or without the ability to zoom in and out, or move the camera around to various degrees). If DAO had only been topdown it would have been perfectly fine, but i do appretiate the fact though that I can zoom in for a more of a 3rd person like view. The 3rd person-like view is normally how I run around in DAO, since I prefer using the wasd when run (rather than clicking my wayforward) in that game, and because sometimes it is easier to see your surroundings in the 3rd person view. But in combat I do not like using wasd, and rather click my characters to where I want them, at which point the topdown/isometrical-like view is prefered. In minor to medium sized battles, and/or easy battles, I tend to stay in 3rd person. But in larger and/or difficult one, where I feel I need a better idea of the situation, I go to the max zoomed out view. Especially games that are turnbased I would say benefits highly from a isometric and topdown view. I have played 1st person-view turnbased games, and they are ok... but it always feels a bit awkward, and I always wished there was an isometric/topdown view, or a 3rd person with a free camera rotation at the very least.