Except for one time, all the times I've been involved in player evictions have been as a player rather than as a GM. Usually, when I GM, people get a sense of my unique style and if they do not like it, they move on reasonably soon.
The one exception to this was when I had two difficult players, one of whom had quit the campaign in two separate huffs, only to return for a third time. Back then, because he was dating my ex, I didn't trust my own impressions of how obnoxious he was being because I figured I had plenty of subconscious reasons to see him in a bad light. In the first session of the game, he came up with what is, for me, the emblematic bad player quote: "A 17? A 17!? If I knew I had to roll a 17 I wouldn't have even come tonight."
The other player was a close friend who had, up until this game, only played wizards. In this campaign, he decided to play a paladin. He was the worst paladin in the history of gaming. I've never been a fan of alignment rules and have found them totally non-descriptive of human behaviour so I am pretty laid back about alignment in my games. But this guy played the paladin as the very embodiment of Lawful Evil. Furthermore, he insisted that acting like a law-abiding sociopath, obsessed with gaining material advantage over others was the very essence of what it meant to be Lawful Good. 
While both players were, as you can see, a trifle problematic on their own, every time there was loot to divide, these two would be at eachother's throats, the paladin's player going into a kind of passive-aggressive pouting fillibuster and the ex's boyfriend (who went through more than one character in the game) hurling ad hominem attacks at him (in one situation, this went on for 2 hours of a 3.5 hour session). Weirdly, both characters, unlike their neutral-aligned, barely theistic party-mates, played their characters are narcissistic paranoids, unable to do anything altruistic, even if it meant hundreds or even thousands of innocent NPCs dying. 
Eventually, I cancelled that game. While the other players were quite empathetic, the two antagonists, whom I would take refuge in the kitchen to hide from, were deeply disappointed; they maintained the campaign was one of the best they had ever been in. 
As a player, I have participated in the eviction of fellow players on two occasions. In one case, we had a player who was a trifle odd anyway who developed some kind of souped-up Seasonal Affective Disorder which seemed to us a little more like Seasonal Affective Psychosis. She decided that she was a worthless person and that the only good thing in her life was her character. A memorable quote in her case was, "I don't care if people don't like me. But if people hate Emmanuelle or want to hurt her, what it means is that they hate everything good about me and everything I want to be."
Needless to say, this presented some serious problems for the GM when NPCs interacted with  the character. This was not helped by the fact that the GM was running a campaign world that was incredibly brilliant and filled with references and metaphors that only I was getting. As a result, he had begun to use the already semi-toxic game dynamic to encourage people to act our subconscious resentments towards the other players, thereby yielding a situation where not only were NPCs working against the problem PC but so were two of the other players. 
In the end, we basically voted her off the island. Everybody else in the group agreed it was time for her to go and saddled the GM with the problem of breaking the news to her.
In the final instance (and I feel blessed to have only been through this three times), when I first moved to my present location, I joined a group that was on the edge of collapse because a number of the players had moved away. The GM, unfortunately, had a total open door policy and accepted anyone into the group who asked to join. So, we ended up with the player who took the jittery, paranoid, desperate-for-approval, hyper-geek persona to the next level. 
In the first episode, which was the first of three wrap-up episodes for the previous campaign, the abandoned 17th level character he was running, when faced with a relatively benign challenge, cast Wish. I remarked, "Are you sure you want to do that with the experience point cost?" The next episode, he began to complain about how he would never have cast Wish if he knew it cost experience points. For the remaining two episodes, his character spent his time seeking out a wish-granting magic item so he could Wish his lost experience points back.
We then began an equestrian campaign based on Northern 14th and 15th century Eurasia. He insisted on playing a Rogue and his wife (yes -- this guy had a wife... sigh... I console myself with the fact that she may have been motivated to marry him in part to obtain Canadian citizenship) a Monk. Over time, he became more and more frustrated because we were riding horses everywhere, despite the fact that all the setting material we were handed, before we did character creation, told us that's what we would be doing. Finally, he blew up at the GM over the fact that the campaign was what he was told it would be. After he expressed he wasn't enjoying the game, before my GM could say something nice and conciliatory, I suggested that the obvious remedy was for him to leave the game and never return. So he did. I may have received bonus XP for my remarks.