Hardest guitar chords that are worth learning?

['59]

So the difficulty to play the chord and how tech the chord actually is or how advanced the music is aren't proportional. Learn how to spell every type of chord and use fingerings that are useful, not fingerings that aren't useful. Or go by what style of music you're focusing on and what type of chords that music uses. As you can see, you can play tech chordal music without spanning your fingers at all. From the jazz guitar forum:

What's a good resource to learn how to do this? Like what's a good book I could read where I could be able to see a set of notes and say "ah yes, an Emaj9sus4" or "Hmm, a minor chord sounds good here because the minor third interacts with the previous chord in *this* way"

 

[Clint 55]

The best resource to learn how to do this is to work out a song with the melody note on top and the chords beneath. The benefits to this are it is an achievable step, it's practical and gets you playing actual music, and it teaches you chords along the way. Take any song you like that you think has some chords and melody to it and work it out. You can start by only playing the chords. Try to spell them out but if you can't then look up how to finger them. Also learn the melody individually. If you can't read then learn it by ear, by tab, or by a youtube tutorial. The melody or top note is the primary way chords link between each other. The bass notes of the chords are the next most important way chords link between each other but you'll automatically be playing that with the chords. Here is an example of a tune with a bit of chords and melody, but you can pick any song you want.

If you like this style of playing, there are ways to approach it more deeply, but just playing the chords to a tune with some reasonable harmony to it with the melody on top is a lot of very beneficial study that many intermediate level players don't even master. Jazz is mostly this type of study, but I recommend focusing on music that you like.

Here is an example of a guy who has mastery of all aspects of linking between chords. The melody, the bass, and sometimes inner voices. Check out his channel if you like his playing and want to learn more.