Saints Row IV ends with a dance party. It's a lazy and cliche way to wrap things up, but it's kind of delightful. Seeing the characters express themselves through dance, from Matt Miller's dorky clutz routine, to Kinzie's inexplicably over the top stripper routine, to Johnny Gat's wounded machismo when he fails to do anything even resembling a dance, it emphasizes the main strength of the game's story - we get one last chance to spend time with these characters before the series is rebooted or abandoned.
And Saints Row IV really does feel like an "end of an era" game. A lot of your old foes make a return to fight alongside the Saints, and it's almost like a last, nostalgic tour of the rogue's gallery. Shaundi's character arc gets a satisfying conclusion as she comes to terms with her survivor's guilt and makes peace with her hedonistic younger self. And the game's whole "hold nothing back" approach to relentless absurdism suggests that no provision is being made for the setting's longevity. In the end, Zinyak is dead, the Earth is destroyed, and the Saints are in control of an interstellar empire. There is almost nowhere left to go after this (though I for one would have loved it if Gat Out of Hell had been a full-fledged afterlife-themed SR5, and not just a collection of minigames bundled into a standalone expansion).
As far as endings go, it's pretty satisfying. The progression of the Saints Row series is one of the most remarkable in gaming and it's amazing to see its transformation from game to game. The Saints' rise from outcast street-gang to galactic saviors is as ridiculous as it is implausible, but if you stick with it, you get a thrilling sense of limitless escalation. The audacity is breathtaking, and it makes you feel audacious for playing it.
I guess you could say I enjoy the series quite a bit.
Fortunately, this is not yet the end for me. I've got two big DLC packs left to play - "Enter the Dominatrix" and "How the Saints Save Christmas." I'll probably blow through them tonight and be ready to move on to another game tomorrow, though I have a feeling it will not be without a certain amount of sorrow.