Barb is a bugged mess and frustrating to play at times because gameplay relies heavily on resource and cooldown management. Majority of builds consist 3 shouts, lunging strike, wrath and a core skill (hota or ww) because other options just feel clunky and inconsistent.
Necro bone spear is just far above anything else. For majority of builds, Decrepify, Corpse Tendrils, Blood Mist and Bone Storm feels mandatory. Minions in early game without paragon boards are just worthless.
Sorc is a meme class where your skills slots and enchantment slots are picked for you by blizz. Every build, regardless of their chosen element, has to utilize one specific aspect (control) and one specific node on the tree (devouring blaze). It feels utterly stupid being compelled to use freeze and burn on a lightning build in order to do meaningful damage and also use flame shield or ice armor in order to survive. I honestly cannot comprehend the though process behind designing such mess of a class. Needs complete overhaul imo.
Druid is the only other class that has potential to have variety of solid builds. You can have fun with lightning storm, claw, shred or bear builds. However, shapeshifting has significant advantages over a pure human build and bugged earthen bulwark and tempest roar tornado are just far above any other build. Also grizzly rage feels mandatory. Companions are just supports.
Rogue on the other hand is just way more balanced than all other classes. No core skill has huge upside compared to others. All specializations are solid and open up different play styles. Everyone uses shadow step and dash but they are not completely mandatory, just fun. All imbuements have their own advantages and you don’t even have to use an imbuement if you want. Caltrops and smoke grenade are not widely used but they are also solid options. Ultimates do not have significant advantages over each other. Some uniques can also be utilized. My only gripe in terms of build variety for rogue is that crossbows are just too good compared to bows as a stat stick and puncture is too good to pass. All in all, you don’t feel compelled to use a specific skill or item in order to survive high tier nms or do meaningful damage unlike other classes and not a single build (except that bugged poison aspect) have significant upside over other builds.