Fave album, of course, is Ænima. Wasnt a huge fan of Tool when they were doing there straight-up rock stuff like Undertow...and, even though it is good, not a fan of their newer stuff. (Schism and Jambi are way overplayed) Ænima is right there in the middle. A nice mix of straight rock and psychedelic/ambient rock.
For your other question...I gotta say the Ænima is my favorite song. The reason behind that: I hate California.