For me it's brotherhood of blood, then dragon bros, then blue sentinels, then Bellbros... The rest are really bad IMO, the ratbros are... Cheesy, and too gimmicky for me... It's kinda neat, I guess... But both the grave of saints and the doors of pharros are kind of superfluous and crappy levels IMO...
I don't really praise the sun lol, never have been fanatical about coop as I've never had any issue running through a level on my own, I'll coop with bosses, but meh... Plus the heirs of sunlight just felt tacked onto the level where ds 2 starts to go downhill, namely harvest valley... From that point on the game takes a turn to the chore to play... Not meant as harsh as it sounds, it's just where I started to lose interest in the world itself, it's be shameful if there wasn't a sunlight covenant though, as that's a staple IMO, and it needed to be there... Well, not where it was tacked on, rather somewhere that made some form of sense instead.
Ratbros are a cool idea, I just wish it was tweaked a bit
Every man has inside himself a parasitic being who is acting not at all to his advantage