The real question is: Do you want to make yourself laugh, or be a good person?
If you would like to take encounters with a person you don't like and be a good person, then you should do the opposite of any impulses you have. You should be polite, friendly, treat them as if they were you. And of course, you should always want to treat someone as awesome as yourself in a grand manner. Initially this tries your patience to absolutely no end,but eventually it has potential to pay off. The person you don't like is never really offended, and you should end up being a more patient and accepting person.
Now, if you wanted to turn someone you don't like into pure entertainment at their expense, it is FAR easier. The answer is simple: Sarcasm.
Sarcasm is a beautiful art, a type of humor that smart people use. Usually, at the expense of not-so-smart people. Now, in many cases, you probably don't like someone because they operate with less brain power than a bag of rocks that has a leak. So, besides little things like "conscience" and "morals", there is no reason not to use such a person for your own amusement.
For any Scrubs fans out there, Dr. Cox is a pristine example of sarcasm for people that are not too well liked. The hilarity that ensues is normally enough justification for any guilt that may be felt. So basically, just be a clever jerk and use the person you don't like as your metaphysical prop.
But, that's if you don't want to be a good person. I'm not gonna say what you SHOULD do, these are simply methods of HOW to deal with such people.