While I was surfing online, reading up on other ways people play BANG!, I read one interesting variant from Raman Ohri over at Board Game Geek. He called it the "Secret Characters" variant, and described it thus:
Instead of all of the players revealing their character cards at the start of game, they are all kept face down. The character is only revealed once you use your power. You can choose NOT to use your power (and therefor not reveal) if you like. Each player has the same number of life points as normal.
I think that this variant is really interesting, as your role can be a really negative thing at the beginning of the game, especially if you are a really offensive character like Willy the Kid or Slab the Killer. It is also extremely useful for the likes of Vulture Sam (but perhaps OP for him? Of course, some hate Vulture so much that this might be one way that they start to like the guy). It makes it difficult for the Outlaws to figure out the best offensive strategy against the Sheriff, but also makes it difficult for the Sheriff to infer who his threat is. And revealing your role can be an act of deception, making others wonder, "I wonder what role he has for him to reveal his character so?"

It is also really fantastic for 3-player BANG! I hated it how the general strategy was for the 2 weaker characters to gang up on the stronger, while the stronger tried to knock off the weakest. You just flipped a coin that you were attacking the right role. With the characters hidden, it creates a little more balance and an interesting situation for the players to wager when the best time to reveal their character is. If anyone has tried out this variant, and noticed anything else about it, I would be interested in hearing their thoughts.