I couldn't leave well enough alone, so I began using the Cyberpunk 2020 rules for just about everything. Interlock (as the system was called) was versatile for modern and future settings, ultimately configurable and easy to understand. I've used it to run plenty of non-cyberpunk games, from Aliens to The Morrow Project, as well as Star Wars.
My Aliens mods were one of my most appreciated adaptations, at least overseas. For some reason, they were really quite popular in Poland, of all places. They haven't been available online for some time (at least, not through my wife's CP2020 site), though I've considered posting them again. There are a few other Aliens adaptations out there (at least one of them using CP2020 as a basis; another used Millenium's End, IIRC), but being the snob that I am, I'd only ever use mine. I appended them at a later time with rules for the title critter from the Predator films, too.
When my rules were written, the only sources I had available were the theatrical release of the Aliens movie, the novelization of the film, the Aliens role-playing game (produced by Leading Edge Games, using a scaled-down version of the Phoenix Command rules), and a little-known small-press game titled Bug Hunt (not to be confused with TSR's Bug Hunters expansion for The Amazing Engine system). The Colonial Marines Technical Manual was not in print at the time, and if it had been, it would have proved to be quite inspirational.
The original inspiration for the Aliens mods I wrote was, of all people, Josh, my friend Will's older brother. After the movie Aliens was released, Josh wrote up his own statistics for the Colonial Marines and their xenomorph foes using Revised Recon as a basis. The games he ran using those rules were pretty memorable, and (like many of his other games) they typically ended with the PCs being violently killed. We loved those games.
Like Josh's games, the ones I ran using the Interlock system and my own Aliens adaptation often ended with the PCs dying. There was some playtesting that needed to be done, as my initial take on the "acid for blood" rules was a bit unbalanced. In some cases, the PCs were their own worst liability. I even went so far as to run a multi-session Aliens mini-campaign, which involved corporate interests, a xenomorph infestation of a colony world, and synthetics/androids programmed for combat duty. That game was a great deal of fun.
For my Interlock Star Wars adaptation, I started with equipment conversions. I may have overdone it, but blaster weapons in that game were freakin' deadly. The PCs were Imperial conscripts taken from some outer rim hick planet, given shoddy training, and sent off on a suicide mission on a moist jungle world (with a stop on Tatooine for some much-deserved R&R, not to mention a drunken brawl with a group of Naval troops in the Mos Eisley Cantina).
One of the characters, unbeknownst to the rest of the party, was an Imperial spy, sent to keep an eye on the rest of the conscripts. What was amusing was that one of the other players had assumed that a specific NPC was the Imperial agent, and would confide all of his anti-Imperial sentiment in the actual spy. This wasn't revealed until the game ended, at which time there was much lamenting and gnashing of teeth.
And then there was my Morrow Project adaptation to Interlock. Not much needed to be done here. Mostly, it was a question of adapting modern day weapons to the system. I changed things around a little. As the PC team was one of the last to be put into hibernation prior to the nuclear holocaust, they were armed with somewhat more advanced weapons (namely, H&K firearms). Once awake and out of their bolt hole, the PCs first encounter was a giant bear in the wilderness.
What the players didn't know was that there had never been a nuclear holocaust. Instead, the world had ended due to the return of the Old Ones (of Cthulhu fame). This became somewhat more obvious when their first encounter with actual people involved a cultist community that had kidnapped their NPC medic. A bloody battle between the armed PCs and the somewhat less armed NPCs ended with the medic's rescue and the entire cultist community population being shot, blown up, or run over. For some reason, the game was short-lived. I don't think it clicked, and I can't necessarily remember why. It just didn't.
So, yeah, I did a lot more with Cyberpunk than running Gibsonesque street-level campaigns...