Any of the endings that actually carry through. Obviously the ones where he completely loses/disappears are dead-ends. But as long as he "wins" one way or another, he continues on, and the consequences will be reflected in little ways in the future games.
Imagining Mezz after 4-5 Slut endings where his brain is complete mush after becoming brainwashed to bend over for every criminal species in the series XD
would be funny if the brainwashing backfires due to so many diffrent methiods leftovers overlaping turning mez into an agressive hornball with the main baddies scrambling to undo it beacuse everyones a bit sore now in more ways then one.
