My favorite game ever, Star Wars: KOTOR 2, has a LOT of problems. Most of the bugs and missing features were fixed with the lost content mod, but the ending is still one of the worst in any game ever. I'd love to see the story fully concluded in a much stronger way. There was so much build-up to nothing, and with a proper ending the game would be near-perfect for me.

Xenoblade Chronicles - Make the in-game faces of the characters prettier, fix the popping.
Dragon Quest 8 - I was going to say allow me to control the random encounters rate (like in Bravely Default), but the 3DS version of DQ8 has the enemies visible on screen, so that's kind of a similar fix.
Zelda Ocarina of Time - I wish the 3DS version of the game could be played on a bigger screen...

Solving puzzles is fun.

Not the ones that require the gamepad.

Probably not xD I meant to say the principle of puzzle-solving is always fun.

Halo, making Bungie the developer again.

Yeah, in puzzle games. Not in action adventure games.

Now that GTA game I can get behind!  Or a forieign city.  Or have seasons like Bully in a foreign city!  Alas GTA really hasn't switched it up with their cities in awhile.

fixed

It all depends on how the puzzle is presented. Action/adventure games have the benefit of being versatile when working within the boundaries of their genre, so puzzles can definitively coexist in them.