Annoying female characters peeps. There might be an existing or similar topic somewhere but...anyway...
I'm sure everyone has at least one female character in at least one manga or anime you just can't stand.

For me, some will be:
Mawaru Penguin Drum - Ringo
Macross Frontier - Sheryl
Suzumiya Haruhi no Yuustu - Haruhi, Mikuru
Full Metal Alchemist - Winry
Shinshi Doumei Cross - Haine (And most Tanemura Arina females...)
and many more...

To my own surprise, I can stand characters like Orihime (Bleach) or Sakura (Tsubasa)...

Hiyori of Hiyokoi. She cries waaaaaaaaay too much. It's as if her tear glands are operating 24/7. I feel irritated with heroines that cry / tear up too easily. Kinda makes the sad scenes annoying instead of heart-breaking.

Nana and Momo from To Love-Ru Darkness

they are so annoying! doesnt care about the age- difference between them and the male lead. acting all spoiled, and using peoples will against their own!