In my opinion, Java. It lacks speed, is barely usable on open-source systems (and only through years of toil by the community), and is just too wordy to use reasonably.
Honorable mentions:
Malbolge for being absolutely useless, a pain to learn, and intentionally confusing.
C# for being Microsoft's version of Java, albeit slightly faster and more portable.
R for being good for statistics and nothing else.
Python for being overused and slow. 98% of the time, anything you write is Python has already been done in a better way and published by somebody else.
Kotlin for being Google's version of Java and being the language that Android devs are forced to use.
QTScript for being a fundamentally bad idea and not intending to do anything new.
Awk for not really even being a programming language and requiring tons of special characters.
Personally, I ended up gravitating to Ruby and Crystal because while Ruby is slow, Crystal works around that, they're easy to read and understand (for me, at least), and Ruby has a nice community. Also, cartoon foxes.