Opening crawl
First exchange between Vader and Leia (and then with the Imperial officer)
The long meeting with Tarkin
The Ben/Luke sequence in Ben’s home (with Leia’s message)
The Tarkin/Leia sequence
And every little thing here and there that give an intuitive knowledge of who’s rulling the galaxy (stormtroopers who basically are the outer rim police; they have street spies; Starships; “that’s the real trick”; etc.)

ANH never lacks any useful information about what’s going on and who’s in charge, political context is in many sequences. It’s always crystal clear, nicely done, never boring or predictable, does not feel “obvious exposition”. Well, we’re talking about one of the best scripts ever written and one of the 2 or 3 best movies in cinema history… If EpVIII could be at least half as good it would be fantastic.