Residence where Shawn steals the Darth Vader and then finds the dead body in episode 6x01 "Shawn Rescues Darth Vader".
Source: Psych Forums
Oliver prepares for his upcoming marriage to Laurel in an alternate version of reality created by the Dominators in episode 5x08 "Invasion!".
Farah and Estevez fight Gordon Rimmer to stop him from getting to the basement in episode 1x08 "Two Sane Guys Doing Normal Things".