Person of Interest
Andrew Benton's Office
Reese follows Andrew Benton to his office and later he gets knocked out by the drug dealers in episode 1x04 “Cura Te Ipsum”.
Decker North & Associates
Reese attempts to gain access to Henry Peck's apartment only to find out that it is a NSA SKIF in episode 1x22 “No Good Deed”.
Source: Person of Interest — Wikia
IFT (flashback)
Finch and Ingram work on the machine in the empty IFT offices in episode 1x22 “No Good Deed”.
Source: Person of Interest — Wikia
Interrogation Room
Kara and Reese interrogate one of Greer's men they captured in episode 3x16 “RAM”.
Source: NYC Permits List
Witherton Insurance
Shaw takes on a temp job at the company where Walter Dang works to clone his phone in episode 4x06 “Pretenders”.
Source: NYC Permits List