I really think that From shouldn't have made 9 Covenants just so they could get an even character alignment square. A few are obviously unfinished, unnecessary, or just plain useless, and the time spent making them should have gone to balancing the PvP or finishing the ones that are good ideas with poor execution.
Those that should have been cut:
Princess' Guard: Useless.
Chaos Covenant: As much as it pains me to say it- Quelaag's sister and Eingyi are my favorite characters in the game- everything in this Covenant should have been able to be done without joining a Covenant, especially as she already thinks you are Quelaag anyway.
Dragon Covenant: Duplication bug excluded, the rewards are worthless, the PvP method sucks,gaining rank requires you sacrifice a rare item with a much better use, and the Covenant and it's leader are completely divorced from the story and world.
This would have allowed them to improve:
Gravelord Servant: Sooo much wasted potential in this Covenant. The PvP concept is good, but it just doesn't work in execution. It would also have been cool if Nito randomly summoned a Servant for his boss fight, with the skeletons only showing up if you are playing offline, and put more incentive into his Covenant besides "Join to get the sword, leave." It doesn't help that to utilize the Covenant, you have to use up an absurdly rare item that you also have to sacrifice to Nito to rank up.
Forest Hunter: Basically a disguised PvP lobby, which is fine, but giving the RoF as a reward was a mistake and the Forest is practically tailor-made for cheesing with it. The Covenant as a whole feels like something slapped together at the last minute.
These are fine:
Dark Wraith
Blades of the Darkmoon: Although the Souvenir of Reprisal should be a 100% drop from the Guilty.
Way of White: it's a Covenant designed to protect n00bs from being invaded before they are ready for it, and that's fine. Doesn't need anything extra as you are supposed to leave as soon as something better comes along.
Sunbros: My only real problem with it is being addressed in the patch