Skylab was a great project and good utilization of leftovers from the Apollo program (although the Soviets did much better with Salyut -> Mir -> ISS when it comes to technology reuse). The end of Skylab was a bit embarrassing as it did not survive long enough to be serviced by the shuttle and there were no more Saturn launchers remaining. Although the damage sustained at launch/deployment makes it arguable whether it would have been a good idea in the first place.

Hubble is also neat (and a testament to the capabilities of the Shuttle as it was repaired twice), and JWST is going to be a good successor.

But there's still very little continuity in the American space program compared to their Russian counterpart. I guess it's partly to blame on the fact the the NASA budget and goals change dramatically when the occupant of the White House changes but I've read some news that they're trying to establish longer term goals. I'm afraid that whoever is the next president will again move the goal posts and set back the SLS + Orion program, which is closest to being the first manned deep space capable space program after the Apollo program.

My point of comparison is the fact that variants of the Russian Soyuz rockets and space craft have been in continuous operation since 1966.