This is from the Game WISH page:

Do you (or your GM) “play favourites?” Do you feel you have to justify your answer? Do you have a horror story to share?

My situation is a little different from those posted so far.  I have to say that our GMs are pretty fair when it comes to players and playing favorites.  The one instance where favorites comes into effect in our games has to do with the number of players that are playing.

A bit of scenery:  We play in a basement on a long card table.  At one end, the GM.  The players sit on the sides of the table, but usually there are more players than comfort room, so someone will sit on the end opposite the GM.

Certain players in our group are more vocal than others.  I am among the more quiet in our sub-group, probably numbering 3 to 4.

Here's the catcher: If we quiet folks sit at the far end from the GM, we don't even get to play that much.

I'm sure it's just an illusion.  I'm sure that we get a reasonable amount of play time.  But the last time we played and sat in this configuration one of our sub-group said "we should start our own game down here" in response to the nearly-endless dilly-dallying up toward the GM.

I've noticed in reading some of the other responses that their GMs don't necessarily pick a favorite out, but one is usually nominated by circumstance.  It has also been pointed out that more vocal players get more attention.  See also: Squeaky wheel, oil.

I see more favoritism happening at convention-style games where one of the friends of the GM signs up for his game and ends up getting all of the attention because he's familiar.  This is not to be confused with bad GM'ing where the GM's style or method of play causes certain players to be cheated for having a conflicting style.

The idea that a GM singles out one player from a group of regulars on the basis that he likes that player best (as opposed to that player being vocal, sitting closer, being more familiar, etc.) seems far fetched.

Of course, on the XP level, there's something to be mentioned here about hidden XP bonuses for in-game roleplay.  Do favored players/characters get more XP from a biased GM?  And how do you award XP to players that aren't really all that great at playing roles, but enjoy the game and contribute?  Interesting question...