The Proselytizer
At my current job there was an employee who made everyone uncomfortable. She left religious pamphlets on desks. When she was told by management that it was inappropriate to do things like that at a government agency, she complained that it violated her religious freedom to be unable to violate other people's freedom to be free from being preached to at work.
When she found out a co-worker was gay she told him it "would be a good idea" if he agreed to go to church with her. Afterwards, we started joking "She wants him to pray the gay away!"
I don't think people would have minded this behavior so much if she hadn't been a crappy employee as well.
She regularly called out sick, or showed up very late, when she was assigned to work on projects or with people she didn't like. One time she told a group of us that she had plans and was going to be gone on Friday. Everyone assumed she had an approved vacation and management had been notified. That Friday, a supervisor told us that she was "out sick." I didn't know it was possible to plan being sick 3 days in advance.
One time I was doing a team project with her and the employee she tried to "fix." While the two of us were working we found she was surfing the internet. When he told her "Um, we're a little shorthanded today so everyone has to pitch in and do their part" she ignored him. A long pause later she asked, "Were you talking to me?"
Management grew to dislike her as well. Since all of us had to go through extensive and expensive background checks and training, we agreed to stay for a minimum of 2 years when we were offered the job. 6 or 7 months after the Proselytizer started working, she quit her job. She revealed that she was planning to go back to school, and had applied a while back. She took the job fully knowing she wasn't planning to stay, and deprived someone else who really wanted the position the opportunity.
On her last day at the job she distributed gifts. They were books written by a preacher known for his "gayness can be cured" ideology. She left them on the desks of people who were nice enough to talk to her (and she erroneously thought agreed with her), and also on the desk of the resident metrosexual.
The metrosexual was very, very mad.