For me the best option was/is the general admission. I was there in 2008 and I bought the top tier tickets. People I was hanging with only bought general admission. I never went to my expensive seats. The place is so fooking big I ended up sitting all over the place in different areas. You'll want to explore and walk around, so IMO, the general admission seats are the way to go.
To be a bit more specific, section J is a good spot to see a lot of the track, the straightaway section is a must, and the South and South West Vista seats are excellent as well.
PS.
Parking lot 1a is great for camping.