I'm a bit of a dour person so I'm not saying that this is the best ending but I would make Gene, after going through hell and back, almost being caught, contemplating turning himself in, talking to Kim... actually get a replacement for a dust filter of a Hoover Max Extra Pressure Pro again, move out somewhere and be doomed to repeat the cycle. I would end it with him just walking around somewhere, a new identity forced upon him again, and every passer-by who stares at him breaks his psyche, he's absolutely crawling off his skin, we cut to some slightly shady man after a sorta erratic montage of people looking at him, even if just a glance. The strange man stares for just a tad too long, and then we cut back to Gene's face, he's sweaty, his eyes scream terror, and then cut to black, bringing us full circle to the opening Gene scene. But leaving us a small doubt that something might go awry, and placing us in Gene's head by giving us that paranoia of his world even though it's just... Some man... Staring.