I don't understand why they have to have Roar AND Whirlwind... Roar should be enough, since it's an TM. They're both Normal-type moves, and they both do the same thing. -shrugs-
I don't like the move Dig. See, if Mr. Dugtrio decided to use Dig on Little Miss Pikachu, Little Miss Pikachu's trainer could switch her out and bring in Sir Pidgeotto so the attack can be easily dodged. Mr. Dugtrio's screwed and wasted one PP.
I didn't like Flash, because it really only served a purpose to light up dungeons (mind you, if you're like me and you've played the games a thousand times, you can get by without Flash).
My other least favorite moves are Sweet Scent, Fire Spin, Whirlpool, Drill Peck (Aerial Ace owns this move, no doubt), Fly, OHKO moves (Sheer Cold, etc.) and Fury Attack (and Pin Missile, the like).