backpacking tent; And I get along with the coat hanger stakes just fine. I never try to force them in but wiggle them around and through the rocks, thus, letting the rock act as a "deadman" to give the stake stability. Occasionally, in loose ground I will double stake my main guy line just to make sure.
campground tents; I use the 12'" nails
Hunting wall tent; No messing around here, 2 ft x 3/4 inch rod, installed with an 8 lb sledge.