2. M-1 Abrams (US)

First produced in 1983. Top speed: 42 mph. Range: 289 miles. The Textron AGT 1500 gas turbine engine gives Abrams a power-to-weight ratio of 26.64 horsepower per ton. Armor thickness: classified. Primary armament: 120-mm M256 gun.

The M-1 scores full marks for firepower and armor — it is the match of any of today's top tanks. The gas-guzzling engine loses points for mobility, though it still scores way above average. For its production rating, the score is low. This is a monstrously complex tank, expensive and difficult to engineer. Arguably the deadliest tank of all time, it gets full marks for fear factor.