Although i cannot give you a the most complete list of essential Z tools, i am sure there are several *cough* TONY *cough* members that can.
8mm - 27mm wrenches, ratchet wrenches, and 1/4in 3/8in 1/2in drive ratchet regular and deep well sockets
1in, 3in, 6in, and 12in extensions for each ratchet drive(2 of each wouldn't hurt either)
universal joint for each ratchet drive
inch lbs torque wrench
ft lbs torque wrench up to 190 ft lbs
an 4" anvil and vise
air compressor
impact gun
air chuck and blower attachment
needle nose, standard, and wire cutting pliers
monkey wrench
C-clamp, one normal and forked
stud remover tool (Tony post pictures of yours there awesome)
88mm piston ring compressor
feeler gauge
cam gear wrench
cordless drill w/ steel cutting drill bits
dental picks
various sizes of flat head and phillips head screw drivers w/ magnetic tips
shop light
jack stands x4
low profile jack
cherry picker
motor stand
oil drain pan
antifreeze drain pan
punch kit
rubber mallet and 3lb mallet
boost tester
compression tester
volt meter
timing light
rolling stool
rolling board(dog bone!)
lap top w/ available wireless internet
a female helper (ahhh moral support)
this is the best list i could come up with and no i do not have all these but in a perfect world this is a start of what i would have. If you have anything to add please feel free to do so, and if you have any questions of "what is that" ask and ill see what kind of pictures i can get you
happy Zing