Best composer that ever lived. People criticize his inventions, sinfonias, and wtc as being too deeply contrapuntal and serious. Once you get past that, there are some beautiful melodies to pick out in the wtc. . . and the suites (especially the partitas) are something else. The goldberg variations are amazing but they're long and hard to get into. I don't really follow his masses or any other church music, and don't really pay attention to music for instruments other than piano either lol. But his extremely popular brandenburg concertos are both easy to follow and complex. And they have a rustic baroque sound.
Good pieces to start with? Many mention the Anna M Bach notebook, which leads into the inventions, sinfonias, then wtc, then you can start to conquer the suites. he's also written some great toccatas, there's the fantasy in cm that kind of leads into the sonata form, some other less known solo pieces maybe? There are also great arrangements from other instruments, like the busonis (but those are extremely difficult). Also overlooked are the bwv 924-943 preludes which are great teaching pieces. The Bwv 939 is popular to learn. They're not as complex but can be used to practice many important aspects of baroque music. For example, the bwv 939 was in alfred book 5 to teach mordents
While I can enjoy melodic composers like schubert or more playful composers like Mozart, Bach is someone that can do everything. And I respect him for that.