Agreed.
Here is a short comparison of the 3 aircraft that I think would be up for debate on that. Obviously these will not tell which aircraft was the best but still some interesting figures.
B-17
Crew: 10
Length: 74 ft 4 in (22.7 m)
Wingspan: 103 ft 10 in (31.6 m)
Height: 19 ft 1 in (5.8 m)
Wing area: 1527 ft² (141.9 m²)
Empty: 54,900 lb (24,900 kg)
Loaded: 72,134 lb (32,720 kg)
Maximum takeoff: 74,000 lb (34,000 kg)
Powerplant: 4× Wright R-1820-97 turbo-supercharged radials, 1,200 hp (895 kW)
Maximum speed: 300 mph (480 km/h).
Range: 3,400 miles (5,500 km)
Service ceiling: 35,600 ft (10,900 m)
Rate of climb: ft/min ( m/min)
Wing loading: 47.2 lb/ft² (231 kg/m²)
Power/mass: 0.0655 hp/lb (110 W/kg)
Armament
13× Browning M-2 0.50 calibre (12.7 mm) machine guns (with optional extra nose armament fitted in glazed nose)
8,000 lb (3,600 kg) of bombs
B-24
Crew: 7-10
Length: 67 ft 8 in (20.6 m)
Wingspan: 110 ft 0 in (33.5 m)
Height: 18 ft 0 in (5.5 m)
Wing area: 1,048 ft² (97.4 m²)
Empty: 52,200 lb (23,700 kg)
Loaded: 55,000 lb (25,000 kg)
Maximum takeoff: 65,000 lb (29,500 kg)
Powerplant: 4× Pratt Whitney R-1830 turbo-supercharged radials, 1,200 hp (900 kW)
Maximum speed: 290 mph (470 km/h)
Cruising speed: 215 mph (346 km/h)
Range: 2,100 miles (3,400 km)
Ferry range: 3,700 miles (6,000 km)
Service ceiling: 28,000 ft (8,500 m)
Rate of climb: 1,025 ft/min (312 m/min)
Wing loading: 52.5 lb/ft² (256 kg/m²)
Power/mass: .0873 hp/lb 144 W/kg
Armament
10× .50 calibre (12.7 mm) M2 machine guns
12,800 lb (5,800 kg) of bombs
Lancaster
Length 69 ft 5 in 21.18 m
Wingspan 102 ft 31.09 m
Height 19 ft 7 in 5.97 m
Wing area 1,300 ft² 120.8 m²
Weights
Empty 36 828 lb 16,705 kg
Loaded 63,000 lb 28,636 kg
Powerplant
Engines 4 Rolls-Royce Merlin XX piston engines
Power 1,280 hp 954 kW
Performance
Maximum speed 280 mph at 15,000 ft 448 km/h at 5,600 m
Combat range 2,700 miles with minimal bomb load 4,320 km with minimal bomb load
Service ceiling 23,500 ft 8,160 m
Armament
Guns 8 x Browning 0.303 in (7.62 mm) machine-guns in three turrets
Bombs normal 14,000 lb (6,350 kg)
special versions 22,000 lb (10,000 kg)
My breakdown is this on which aircraft had the advantage in what:
Speed: B-17
Range: B-17
Service Cieling: B-17
Bomb Load: Lancaster
Defensive Armament: B-17
Based on just these stats each aircraft had its advantages and disadvantages. I go with the Lancaster, B-17, and then B-24 as the 2nd, 34rd, and 4th best bombers of WW2. I still like the B-17 better than the Lancaster though.