There have been about 45 car shows on tv, (and it's no surprise) Top Gear US sucks the most and is the last (lower than My Mother The Car)

http://www.ranker.com/crowdranked-list/automotive-tv-shows-and-series

the top are from 1 to 10;
Top Gear
Overhaulin
Pimp My Ride
Monster Garage
Trick my Truck
Counting Cars
Xtrme 4x4
American Hot Rod
Wacky Races and
number ten: 5th Gear