How Do the Melee Weapons Compare to One Another?
Solution 1:
They are different in terms of reload time, however, they are not different in terms of damage done per hit. The differing reload times will make for an effective difference in DPS though. Melee weapons will one-shot all Common Infected on all difficulties. They will also one shot all Special Infected on all difficulties, except for the Chargers (2 hits), Witches (4 hits), and Tanks (20 hits).
The following is a table in ascending order of rate of fire.
Weapon Hit time Nightstick .650 sec Machete .675 sec Katana .750 sec Golf Club .750 sec Frying Pan .800 sec Crowbar .830 sec Guitar .830 sec Baseball Bat .850 sec Cricket Bat .850 sec Fireman's Axe .910 sec
The Chainsaw is a special case, and it does 100 damage per hit and hits every .1 seconds for 1,000 DPS. All other melee weapons do 500 damage per hit (as calculated on the L4D wiki for the Level A Charge achievement).
Information is from the individual pages of the Melee Weapons on the L4D wiki, which I conglomerated here. Unfortunately, they don't seem to have any information on Gnome Chompski's reload time. :(