The Door*:
By itself:
-Find a computer, access this site and you can acquire other powers.
-If injured, escape to your supply room and treat yourself, possibly after visiting a hospital.
-Heard of an uprising? Escape into your supply room to hide.
-Can't get to work on time? Leave your house to a friend, walk into your work building and find a hidden place to summon the door. Once summoned, live in said door until the holidays, when you can stay with your family/friends.
-Go to Africa (possibly in a jet you pulled out of your supply room) and bring food out of the room to feed the hungry. Bring out medicine to treat the sick. Bring out water for those dying of thirst. All the while, you stay in the luxury of your supply room.
-Disease outbreak? Enter your supply room until it is over, all the while handing out masks, medicine, etc to those less fortunate.
-Can't get powers? Rubbish! Use a computer, get on this site and use it to acquire more powers.
With other powers:
-Godlike Craftmanship: A supply room is a great place to use craft new things, since you have all supplies at hand, things to put into weapons/ armor/tools/etc and you are perfectly safe. If there is a weakness, block it with things you create.
-Ability Imbuing*: See above.
-Immortality: Sit in your supply room for all eternity, laughing while your enemies fail to enter or attack your powers. You will also never be stranded in space, run out of food, water and air and always have a place to sleep. It also enables you to outlive the universe.
-Door to Anywhere: Find a door and use it to teleport to any door in existence. You might be able to use the entrance, but that is unlikely and possibly dangerous.
-Get this power button: Need I say more?
-The Chessmaster*: Now you can attack your enemies in complete safety, with any material desire granted.
-Power of Imagination*: The perfect hiding place for a maniacal reality warper. You also do not need to generate supplies, since your other power takes care of that.
-Conditional Ability Bestowal*: Every leader needs protection for himself, supplies and weapons for his army. Sure, you need to exit the door to initiate a new member, but it is still much safer than just Conditional Ability Bestowal*. If you are paranoid, get a base full of superhumans to protect you while granting powers or give one member Conditional Ability Bestowal* and get them to do the dangerous work.
I think The Door is versatile and works well with many powers.