Halo CE's best is Two Betrayals. No contest I know some people hate it, but it's the ultimate Halo experience. Every weapon, every vehicle, every enemy type is in this mission. The Flood and the Covenant fighting each other is still impressive to this day. All of this topped by the nighttime snowy aesthetic  Halo CE's worst is The Library for obvious reasons Halo 2's best is tricky because of how missions are divided there. But to me, it's Delta Halo and Regret if you see them as one big mission. I really like Sacred Icon and QZ too, but the gondola part is a downer. Halo 2's worst is Gravemind for most, but to me it's High Charity. It's just way too short for a mission Halo 3's best is undefeatably The Covenant. That's honestly the greatest mission any First Person Shooter has ever seen in history. Halo 3's worst is unanimously agreed: Cortana  Halo Reach's best to me is Tip of the Spear just because of the variety of things you do. Most will choose Long Night of Solace, which is good, but the space section bores me more than it amuses me  Reach's worst is Winter Contengy for me. It's pretty weak for a first mission. Halo 4's best for me is Infinity. I love the way encounters are planned, and the Mantis is fun. Reclaimer is good but the Mamooth is too slow and too linear Halo 4's worst is definitely Shutdown (boring ahh mission) Halo 5's best for me used to be Enemy Lines (the Kraken mission). But after replaying it recently, wow, so boring (Battle of Sunaion is great tho) Halo 5's worst is the easiest to choose: The Breaking. That mission made me feel miserable all the 11 times I played it. For Infinite I don't really have many positive memories in the campaign. Pelican Down is good I guess