I just finished reading Twilight (the fifth book in The New Prophecy series, I'm really behind) and I have some complaints:
-How Cinderpelt's death was hardly expected.
-The moments where Leafpool and Crowfeather ended up coming back to their Clans, because Leafpool knew she was still a medicine cat.
-How Tigerstar ends up with two litters of kits (this isn't much of Twilight, it's more of before the cats left the forest)
-How Mothwing doesn't believe in Starclan. Seriously, why can't you just step down from that position if you don't believe in the ancient warriors?
-How Yellowfang and everyone else in ThunderClan waited for Brokentail (or whatever the ShadowClan leader was named) to be killed. (This is a first series rant.)
-Why Ravenpaw never got his warriors name
-The moment at the end of the book I just finished (Twilight) where Brook and Stormfur come to the Clans. Seriously, you're no help for the Clans. And how did you get here anyway?
-How all of the apprentices and kits die.
-How there seems to be way too many forbidden romances (Crowfeather and Leafpool, for example.)
-How Firestar decides not to appoint a new deputy, probably understanding that Graystripe isn't coming back. He probably died by now, because he seems to be the only Clanborn in ThunderClan.
Okay, these are just a few of my Warrior Cat pet peeves, because I could think of a few more.