In which neighborhood (and street) in manhattan would you choose to live and why....

I live on Bank Street in the West Village and wouldn't change that for anything. But, I'm guessing you're a man, so for you, I would say East Village. 8th street around 1st, Ave A and Ave B is really cool. There's a park (Tompkins), a million bars and restaurants (they're legitimately lining the streets in the east part of the East Village) and a great energy. You can find a great apartment at pretty much any price range in this area; but, keep in mind that the closer to 1st Ave you are, the closer to public transportation you are.