The Delta Halo shots remind me how I really don't have a favorite mission in Halo 2--or Reach for that matter. Halo 1 I often play 343 Guilty Spark, Halo, or Silent Cartographer; Halo 3 I play the Ark and The Covenant; and ODST I play ONI Alpha Site and Kizingo regularly. But there were never any missions in 2 that I really ever relished playing in the same way. I've certainly got my least favorites--Gravemind in particular being a "why hasn't this level ended" slog when I was playing it co-op--but like Reach, Halo 2's just stick out as sort of meh, not really with anything distinguishing it beyond gameplay being better than most games (which is sort of damning with faint praise, I guess.)
I haven't played the campaign all the way through in at least three years, though. Maybe I just need a refresher. Does an OXBOX Halo 2 disc work with 360 Slims?