The most powerful move is frenzy plant. Only the grass type starters of each region can learn it from a guy on route 228.
Psystrike
The most powerful rock type move is either rock wrecker and head smash
meteor mash and iron tail
The best normal type move for pokemon is explosion. ;-)
Focus Punch is most powerful, but is un-reliable with using substitute first, considering if the opponent hits you it fails. Brick Break is most reliable.
Frenzy Plant
Psystrike
The most powerful rock type move is either rock wrecker and head smash
According to Pokemon Black and White, its most powerful move is Double-Edge.
In terms of base power, the most powerful move is explosion, then self destruct, but they both cause you to faint after using them.
Avalanche or Blizzard
I heard it is shadow force.
I have one, Its Night Burst, It will learn it.
Sheer cold its a 1 hit KO move.
its called " guard share "
meteor mash and iron tail
If it was a move it learned by leveling up, it's most likely Close Combat.