4.28 avg rating — 79,657 ratings

"Layers and layers of wit wisdom and silliness with and end that makes you feel like you know something new about the universe and how it works!
"

4.50 avg rating — 121,658 ratings

4.26 avg rating — 107,308 ratings

4.20 avg rating — 69,676 ratings

4.42 avg rating — 139,834 ratings

4.42 avg rating — 117,042 ratings

4.32 avg rating — 82,002 ratings