I'd have to say the two most annoying things are Stealth Rock and Permanent Weather. It just annoying when I see a weather lead. I know I use spikes sometimes but, it still bothers me when people spam all of the entry hazards then use freaking Whirlwind/Roar...
Any and all weather abilities. You don't need any skill to use a weather team, so noobs always go with them.
That settles it. I'm starting a new religion. It's called "Misterdarkism".
Undying Rage