Uh, that was actually a point brought up in season 3. Willow got into a ton of amazing schools, but after havinga face off with Faith at the Mayor's office she decided that just going off to be a doctor or lawyer or whatever isn't what she wants. She wants to spend her life doing what they already do; fight evil. Buffy never chose to be the slayer and fight evil even if she's accepted it, but Willow actually decides that's what she wants to do.
also Angel gogogo
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The batman villians all seem to be one big joke that batman refuses to laugh at - SantaRPG