I probably prefer 3rd person Metroid in that I find Super Metroid and Zero Mission to be two of the most enjoyable games I've ever played. But if Other M is any indication for how Metroid is going to continue in the third person then I think I should specific that I prefer 2D Metroid but for 3D Metroid first person is the way to go. For Mario I prefer 2D but for Zelda I prefer 3D as it seems like a natural extension of the original top-down games.
Other M has many flaws, but the perspective isn't one of them (in my opinion). Other M is a 3D Metroid game in 3rd person, and it gets that right. There's no problem there as far as I can tell... the only thing I would have changed would have been to include the nunchuck so that the analog stick could be use, but really the D-Pad works okay and actually better than I thought it would for that sort of gameplay, but an analog stick would have been better. I also would have eliminated the need to switch into 1st person to fire missles or scan your environment, as that overcomplicates things more than it needs to. Super Metroid got it right, because everything was in 3rd person and you didn't need to flip around all the time. That's one of the flaws with Other M, but again there's nothing inherently wrong with the perspective of the gameplay.
However, I agree with many of the complaints people have with Other M... the pixel hunts, having to get adam's permission for everything, emotional Samus, weak dialogue, mediocre graphics, the fact its all inside a ship instead of a planet, and a hundred other minor things as well. Yeah, I agree with those flaws, but Other M also gets some things right too. Its not Super Metroid by any means, but that has nothing to do with being 3rd person + 3D.
Other M isn't the best Metroid game, and almost everyone agrees with that, but 3rd person in 3D has been PROVEN to be successful with Mario, Zelda, and many other franchises over the years. There's no reason it can't be done successfully with Metroid as well. So please don't throw out the baby Metroid with the bath water... give it a chance. Because look at it this way, imagine if Other M was in first person just like the Prime games. Being in FP would not have made Other M an A+ title in and of itself. Would being in FP have fixed the weak story, mediocre graphics, emotional Samus, needing Adam's permission for everything, pixel hunts, etc? Would being an FP have made Other M as good as Prime if it was exactly the same in every other respect? No, it would not have. But at the same time, neither could it being in 3rd person have saved it from being a B rated game, but all I'm saying is give Other M credit where it is due, and if you're going to attack it, then please attack it for the real and legitimate flaws... not for the things it actually does get right.