I certainly didn't, and neither did anyone I knew who played the Halo games. The covenant AI was good for its day, but the flood were braindead. Like zombies. Why on... well, Earth, Reach, Harvest, whatever did Bungie insist on throwing the flood at you?
Halo Wars was the worst offender, I mean, they had to jump through so many hoops to make the flood fit into the game and that was the point at which the game fell apart. In my opinion, they all fell apart once the flood showed up.
I'm ranting, sorry about that. Well, my feelings on the subject are clear, what did you think? Did the flood make the Halo games better, did they make the series worse, or did they merely overstay their welcome?