@fien - I can't deny you have played more games than I have so I shall bow to your superior knowledge!
However, from the games I have played, the one thing you don't tend to get so much in 1st person is the interaction with other characters (other than in cutscenes as you have said - which is a 3rd person element to a 1st person game anyway).
This isn't necessarily better or worse, just different, but in say GK I feel you get to know Gabe better by his interactions with Grace, Mostly et al. which would be missing from most 1st person games.
In the same way you don't get the same feeling of exploration and "being there" from 3rd person games.
