Best: Halo CE - It was so awesome, the mystery of the forerunners and they're huge buildings and the mystery of the flood and the halo's, and a good twist.
Worst: Halo 4 - They totally ruined the best thing about the forerunners which was the mystery about them, and they made Master Chief "the chosen one" just like every other video game ever, instead of being just a really lucky soldier, the didact was a boring villain and not interesting.
I bet you hated the last two seasons of Lost. Writers create a mystery to keep us interested and wanting answers, so they answer some of the questions 12 ****ing years later, and you're mad? Cause **** storytelling, right?
Edit: On topic - 2 > 4 > 1 = 3 > ODST > Reach.
I still remember losing my **** when I found out I'd be playing as an Elite and their Civil War was a good change of pace. People are just butthurt the Arbiter was Halo 2's main character. As for Reach, boring characters, retcons out the ass, and an overall stupid story with worse gameplay put it at the bottom.
I can say I honestly hated the last 3 or 4 seasons of Lost. The story was dragged on way to long for a terrible ending that really made me hate wasting any time watching it at all.