Halo was incredible for it's time. While the original didnt hold up too well, Halo 2, 3 and Reach are still incredible experiences. They could make an entire movie out of Halo 2 and it's remastered cutscenes.

It was like the Half-Life of consoles. I had some of the best times with friends playing Halo, so maybe I'm a bit biased from nostalgia, but they are some of the best games made, just raw fun. The set pieces were amazing, Bungie really knew what they were doing and for the time and the technical limitations, they smashed it.