Pokémon Black & White (be warned: spoilers)

[Cshad]

Whether it's a legendary or not doesn't matter (it is), all that matters is whether its good, or you like using it, or both.

Also, apparently;
There are a few things that Serebii didn't mention:
Rankurusu gets Psywave, not Psybeam
Rankurusu gets Dizzy Punch
Gochiruzeru gets Faint Attack
Chiiramii gets Swift and Wake Up Slap
Piggie bacon gets Take Down

Cool