Power armor sets found in the game world frequently appear to be incomplete (for example, they have the body, left leg and right hand), so the list below contains only locations in which you will find complete Power armors. It was also created in such way so that each place will be linked to only one armor type.
Raider Power Armor
Roadside Pines. Armor will be worn by one of the raiders attacking you.
The armor can be obtained during the When Freedom Calls quest. It can be found on the roof of the Museum of Freedom.
The ark (2) on the other side of the river from USS Constitution (1). The Armor can be found in a cage which can be opened by breaking an easy terminal.
Armor can be found on the main deck of Prydwen after joining the Brotherhood of Steel.
South Boston Military Checkpoint. Armor can be found in the cage behind the building. The cage can be opened by breaking a hard terminal.
Custom House Tower. Go to the back of the building (you will have to defeat some raiders) where you will find a golden sign "35 COURT". Walk inside and use the elevator on the left. Then go up - you will have to defeat 2 robots guarding the buttons. Activate them in order to unlock the door behind which you will find the armor.
In order to obtain this legendary armor part you must complete the Cambridge Polymer Labs quest.