Since this is a similar Decompiler questions these are the best decompilers (as someone who has decompiled hundreds of obfuscated clients the past few days for Warden).
Krakatau an open source decompiler written in python. It gives sloppy output (especially when working with obfuscated jars), but it always decompiles. It has decompiled things that Procyon/Luyten & Fernflower & JD-GUI, etc have all failed on. I strongly reccomend it. Only downside is it doesn’t support java 8 yet.
Procyon\ Luyten good gor your general day to day decompiles. I like to think of it as JD-GUI on steroids. It does decently with obfuscation, but every now and then it fails.
Fernflower Kinda of in an area between procyon, and Krakatau.
After personally examining the plugin I would rate it at Intermediate, it’s not quite well hidden enough/obfuscated enough to be an advanced level. I need to spend more time to work out the way ratings will function so that they are fair. Also I am now trying to finish up the Bans API because it’s way overdue.