So if there is one genre I have never liked it's the Western. Just ask my mom I would cry when i was 3 years old when she watched them calling the Cowboys bad men. On the other hand I really love good science fiction. I've come to find though that some science fiction has western influences.
One such series is Firefly. The short lived TV series that didn't even get to run all 13 episodes of itself on air. But the series has a serious cult following. The whole series has this old western type feeling. However, it is a really great science fiction series worthy of notice. I would have liked to see more about the whole conspiracy thing going on involving human experimentation. But Alas the series was cut short and the movie was kinda meh.
Next in line I'd put the video game series Wild Arms. I've only played the first game in the series so far but this game also has some old west influences. In fact one of the characters looks like a cowboy and uses guns. However, you also have aliens, lost civilizations, parallel worlds, princesses, robots, and magic all in one game. So it's a fantasy, science-fiction, western hybrid. The story is really good as well. I'm definitely going to get the next game.
Then you can't forget Stephen Kings Dark Tower series. You have an old west type setting with gunslingers and outlaws. But as you go though you realize this is like a chivalric romance. Roland and his band are knights on a quest. In fact you have references to Chivalric romances as well as Stephen Kings other works. There are references to the King Arthur Cycle, The Charlemagne cycle as well as Akira Kurosawa's The Seven Samurai. And there is nothing I like better then a tale of samurai or knights going on a quest and The Dark Tower gives me that even though it has a western feel.
Last but not least is The Princess of Mars, first book in the John Carter series. It takes place after the Civil War. John Cater and his buddy having left the south after being on the loosing Confederate side. They find Gold in the west. When getting supplies his buddy gets killed by Apache and John Carter rushes into things trying to save him. Somehow in escaping the Apache he finds himself on Mars. So in a way this is also a western but not a western. Afterwards you can still find some western elements but mixed into the science fiction. I've only read the first book so far but its definetly a great read.
So I have to say not everything with western elements is bad. You can have gunslingers in deserty dying worlds and find something wonderful. They could really be knights in disguise. Also all the titles I mentioned above have wonderful stories.