It's funny. I recently wrote a young-adult novel (Riese: Kingdom Falling
) in which, ultimately, all but two short scenes were told from the POV of the main character. So, yeah, I could have conceivably done that book in first-person, but, personally, I still find third-person more comfortable and less awkward to write in. And I still think that describing a character from the outside makes them more distinctive and easier to visualize than some amorphous "I."
And third-person doesn't stop you from getting into the heads of your protagonists. I Am Legend
by Richard Matheson is written entirely from the POV of the last man on Earth, but it's written in the third person . . .