@Salyx my take on it:
Chaos Warriors - too expensive and low numbers for any purpose really. Needing 10+ models for their armour Rerolls a d not having any rend kills them for me.
Marauders - any offensive mark works like a charm
Knights - need to many buffs to be effective, I‘ll take them for style reasons edit: I am honestly shocked these don‘t have a 3+ save and a 3+,3+ even for lances
Shrine - great, works with every build
Varanguard - overcosted but they can work due to their speed and volume of attacks
DP - works everytime as well (if you‘re not stupid like me by reading the weapon setup wrong and thinking he could only have one weapon...)
War Mammoth - Distraction carnifex. Works great with Khorne and Slaanesh (or Nurgle for tankiness). It can easily wipe entire hordes with a double pile in and it denies a huge area (good for holding and blocking objectives), debuts bravery on the charge, which opens up combos.
Furies - situational but good for attack-fleeing onto objectives
Cultists - only IG and The Fang have some uses
Warcry heroes - skip these
chaos Lord on foot - the range is just too short, but he can work really well and is punshy as hell
Krakadrak lord - too expensive but has potential
Darkoath heroes - these are okay, sadly they lack any mark which makes them not synergising with their own faction.
Sphiranx - good effect but a bit expensive since the rest of the stats are just bad?
Chariot - hard skip (imo)
Manticore Lords - hard skip due to looking so bad I don‘t even want to touch the model
Gaunt summoners - awesome but only due to summoning undying horrors
Archaon - Great, has it’s uses as beatstick, but seems a little underpriced (well that‘s a first for the army)
Marauders horsemen - big meh, what exactly are they supposed to do?
chosen - fugly models, hard skip for me.