>>95564156
Maximum's the frontrunner for me, but most of them have at least something you'd want to steal.

MH1
Lots of adventures, and the only significant source of fluff for non-North American areas
A classic 90s pile of disparate subsystems (two different damage systems, two different hacking systems plus a pair of minigames, etc.)
Line was cancelled before the combat supplement was released, so combat specialists don't have much in the way of toys
Setting is the classic "post-apocalyptic wasteland full of wacky gangs and mutants, dotted with the occasional mega-city". Unless you live in Australia, then life is pretty good.

MHM
Massively chopped down the NPC statblocks so you're going to have to make a bunch of your own if you want a wider variety of mutants
Psychics are now a proper character type instead of being tacked onto the network rules, and a new category of items is added that are super-advanced tech developed on moonbases that let you do things like shoot down incoming missiles with a pistol
All the missing stuff from the 1e combat sourcebook got added to core, so you get to have all the advanced cyberware/bioware rules etc.
Simplified the profusion of subsystems to make the game easier to wrangle.
Setting has advanced to have megacorp terraforming attempts start working, so a new wild west expansion phase is on. More hopeful than 1e, but still has room for the classic style of play
Exercise extreme caution with the freer lifepath system from the supplement, it's very easy to break it over your knees