I've used Seriin for just about everything, including forum names and my XBL ever since putting it together from random letters years ago while naming my son in a Harvest Moon game. Other I use on occasion are Dyne Irving, or Skw'd (pronounced "squid").
Unless it is a pokemon game, then I generally just call my character Jamie/James, and have a large group of nicknames I use for the pokemon. Most of the time the 'mons nicknames is a traditional name I've used for every member of its species for a while now. For example, every Torterra I get is nicknamed Mayonaise, and each Umbreon is Crypt.