If you can tolerate 70s animation, Galaxy Express 999 is a classic and has somewhere around 113 episodes. It's very episodic, and most of the planets visited are just kinda there with no lasting effect on the plot or characters. Most of the episodes are good, but if you watch a lot in a short period of time, you'll probably notice that some episodes are very similar to others. Poor, struggling mangaka are very common characters for some reason.
If you've ever seen a willow-y blonde in a long black coat and fuzzy black hat in another anime, she's probably referencing or cosplaying Maetel from this series. It's worth watching an episode or three to get in on that joke. There are also a couple movies, but I don't know enough about them to make a recommendation.