Gamera
I don't know the specifics of different M60 versions but it looks cool to me!
It's not quite as complicated as German armor, but the M60 series consists of four basic versions; the original M60, also called the "Slick 60", M60A0 or "A-nothing".
That first version is very similar to the final version of the M48 series tanks with a 105 gun instead of the M48's 90 mm. A lot of people will mistake an M60A-nothing with an M48A5, including old 19E tankers.
The Slick 60 served for decades in USAR and ARNG units, so the tank continued to receive upgrades that appear on later versions of the M60A1 or M60A3.
The next version is the M60A1 which served even longer and received so many upgrades that it would take a book to list them all. The final version of the M60A1 used by the USMC was the M60A1 RISE/Passive which served during Desert Storm.
The M60A2 had the shortest life and used a funky looking turret that fired the 152 mm Shellelagh missle or a cansiter round. Most of those tanks had the turret removed and became AVLB bridge launchers.
The M60A3TTS was the final version used by the Army. They added a Tank Thermal Sight (TTS) that was very effective and a laser range finder (LRF). There are a few more upgrades, but mechanically it was virtually identical to the M60A1 RISE/Passive. The improvements were to the fire control system versus the automotive capabilities.
The main visual differences between the two main variants, the M60A1 and M60A3, are the thermal sight housing (aka "dog house"), the thermal shroud on the main gun, crosswind sensor mast, and the laser range finder housing.
In the little photo of me in my TC hatch, there is a round blister below the cupola. It is the LRF housing and has a small brass padlock on a little door flap. The laser range finder was considered a direct fire weapon and could blind people. The cover is to prevent it from being fired by some soldier just messing around. Yeah, that happened because they didn't treat it like the weapon it was.