Police Quest I: In Pursuit of the Death Angel (VGA)
Look at Paul in prison to get a reference to Leisure Suit Larry
Look at the board outside the Blue Room for a reference to Stuart Moulder
Read the posters at the Sin City (where the stolen Mercedes is stopped) for various puns, including a reference to Tom Cruise and Nicole Kidman.
Check the personel file in the LPD computer. Several of the last names are from Sierra employees, such as (Bob) Ballew, (Sabine) Duvall, (Josh) Mandel, (Lorelei) Shannon and others.