Heinlein: The Green Hills Of Earth
Asimov: I, Robot
Blish: They Shall Have Stars
Anderson, Psychotechnic: The Psychotechnic League; Cold Victory
Anderson, Technic: "The Saturn Game"
Niven: the Garner/Hamilton period
Pournelle: (straight to interstellar)
Blish's four volumes are respectively interplanetary, interstellar, intergalactic and inter-cosmic. Anderson also goes intergalactic and inter-cosmic although not in his future histories.
It seems to require an extra leap of the imagination for sf writers to get outside the galaxy. Asimov only just starts to think about it at the end of his future history. Having populated the Galaxy only with human beings and with robots whose behavior is constrained by their relationship to human beings, he begins to ask whether there might be other kinds of intelligences in other galaxies.