Important: read subtext.
Ah, the guy who has been there since the very beginning. Dave Panpa. For a basis, here's what happens to him throughout the timeline:
Given how he survives every ending in Escaping the Prison, we rule those out since we know he gets fired and becomes a security guard. Same for Stealing the Diamond, we rule those out because we know he gets captured by the Toppat Clan no matter what.
Infiltrating the Airship is where it gets tricky. We know he survives in RPE and RBH, and is freed in GSPI. However, his fate in PBT is unknown, because it's possible he died in the crash, survived and managed to escape, was killed in action, or was rescued by the government. In the case of the first option, he probably would have survived and gotten a day job, given how Henry also escaped despite being in the middle of nowhere in EtP. Same thing if he was rescued by the government. If he died in the crash or was killed in action, then that's the end of the run for him.
Of course, in Fleeing the Complex, we know he would be alive in the RPE and RBH paths. If Henry never chose those, he's either freely at home, or dead.
In all GSPI endings in CtM, he's obviously alive and likely working a day job. As a result, he is alive in CeO, TT, VH, SBO, and also MBH (though he is only freed later on).
In Free Man, he's still in custody, and unfortunately ends up starving along with the Toppats that are stranded in space.
In Capital Gains, he likely remains in custody, unless the TC was in chaos due to the death of their train division and RHM. In which case, a weakened TC under Sven (who has the charisma of wet toilet paper) would be easily raided by the Gov't, who would free Dave.
In Little Nest Egg, he remains imprisoned.
In Jewel Baron, if he's still in custody and didn't escape or die earlier, he gets vaporized when Henry reflects Supreme Dominance back to the station.
In Pardoned Pals and Toppat Recruits, he's likely already dead, or free and working a day job, as usual. If still alive and in custody, he dies in the former and remains locked up in the latter.
In Stickmin Space Resort, it's the same story as before. But if Dave's still locked up, it's possible Henry would give him a chance to reform and work for him, or allow him to be sent back to Earth. Unless Henry is an ass, in which case he'd remain in his cell.
In Toppat Civil Warfare, we are well aware that he's alive, and joins Henry's Squad. If only there was a continuation...
In Toppat King and Toppat 4 Life, it's likely he remains imprisoned for the rest of his days. Poor Dave :(
In Revenged, he dies from either the Y-type move, or the Airship crashing into the Orbital Station.
TL;DR: Dave is alive but incarcerated in many endings, dead in some, and has an ambiguous fate in others.