Psion
Adventurer
6.) "Feint and thrust" - Similar to overextension (above), you draw the enemy's forces away from his stronghold, then strike a crippling blow to the stronghold or take it over entirely (#5 above) while he is away.
This has a lot of appeal to me. Sort of a divide and conquer. The villain relies on his henchmen to do a lot of his dirty work, but doesn't entrust (or cannot entrust) his minions with enough power to stop the PCs when he is not around. A quick distraction could dismantle his plans, though if the villain is truly staggering in power, this may not be sufficient to permanently deal with him. Hmmm.
Yes, I know this one has other religious implications and figures that could be substituted for Aslan, but let's just keep it in Narnia, okay?
Galdalf doesn't count?

10.) The "bell around the cat's neck" method - The enemy is using a ritual to gain or maintain power. Some fool must go swap out one of the material mystic components the guy is using without him noticing; this creates an Achilles Heel for later exploitation ("the Death Star shield is down! Go for it!"), robs him of power without him realizing it (e.g., the Biblical Sampson when his hair is first cut), or destroys him instantly when he tries to use the "wrong" item, thinking it to be the right one.
This has a lot of appeal. Instead of the explicit weakness, the characters can try to make a weakness/use trickery. Puts it in a slightly different realm. But sometimes, getting players to seek weaknesses without prodding can be a bit tough.