Rank or state which you like, dislike or are ambivalent towards. List numerically, rank them in tiers, separate or combine the loyalist and traitors however you like. Maybe just state your favourite/s and least favourite/s leaving the other ones out. Whatever you want. I'll do mine
Luna Wolves/SoH/Black Legion
I have a general preference for the Chaos legions because they were my first and third armies and the bad guys are usually more interesting. AL and TS are the chapters I always root for in the fluff because they both have interesting backgrounds, both turned traitor for justified reasons, they're both underdogs in a way. I like their primarchs. Part of the reason I hate the Space Wolves and Ultramarines because they've done over my favourites in the past
Raven Guard are inoffensive, one of the least significant of the first founding chapters, have a tragic back story (the Istvaan thing), are rarely used by 40k players, I like Corax, like how they look and their playstyle etc.
Tier three are the legions I like and tend to root for depending on who they face. Tier four are similar but slightly lower. Word Bearers were my third major army but they're a bit twisted for my liking. Night Lords have a cool back story, colour scheme and play style but are also pretty evil. The loyalists here are chapters I neither like nor dislike.
Tier five. Ultramarines are boring, always irritatingly heroic in the fluff and the army every beginner chooses. The Alpha Legion thing doesn't help. I sort of liked EC before they fell to Slaanesh but after falling they're hard to empathise with.
Space Wolves turned on my poor Thousand Sons- nice job forcing an entire legion to turn against the Imperium. Their wolf fluff is lame and the Viking thing is a bit cliched and over the top for me. To hell with them. Part of the reason I have the World Eaters in tier four is the fight they had with the SW pre heresy
Anyway- thoughts? Who do you like and hate?