Because I occasionally search for this information myself, I’ll post it here for future reference to me and others. A list of journals in game studies in no particular order:
Games and Culture (Sage)
Journal of Gaming and Virtual Worlds (Intellect)
International Journal of Games and Computer Mediated Simulations (IRMA-International)
Entertainment Computing (Elsevier)
Simulation & Gaming (Sage)
Transactions of the Digital Games Research Association (ETC Press)
Collected from uta-mailing list GAMESNETWORK. Feel free to point out journals I missed.
Update: A more complete list is now available at: http://digrastudents.org/games-research-journals/