Fairly different games, 2006 was more of a classic linear narrative shooter in the early 2000s tradition but with some brilliant mechanics and novel guns, and a pretty cool storyline (if a bit b-movie-like). 2017 offers a freedom of approach and exploration that’s uncomparable, but it’s also more stern in atmosphere and tone. I don’t have a favourite, but now you made me want to do a replay of 2006