Okay, so here's a handful of ideas.
I did do a quick sweep with the search function (by quick sweep I mean the first 2~3 pages of results) and didn't find anything, so here' hoping these aren't word-for-word copies of other SCPs.
I appologise that this post is so long.
"Magic Chessboard": A chessboard that can be used to allow two players to wager separate aspects of their existence to be forfeit to the other upon the game's conclusion. almost anything can be wagered, such as material possessions, biological traits, relationships, freedom, literacy, and knowledge of a subject to name only a few.
The Sepdians (Not Final): appears to be a single entity, but changes form and personality everyday; Lord Sunday, Lady Monday, Mr. Tuesday, Wednesday, Mrs. Thursday, Archbishop Friday, and Sir Saturday. Each wears a full-face mask, so facial features cannot be observed. claim to come from an unknown/nonexistent country (Sepdia)
"Death Chair": A chair whose arms and back look like the 2-dimensional arms and torso- with head- of a person. the chair is harmless until you sit in it for the first time, after which symptoms begin to show: Stage 1- generally heightened anxiety and slight compulsion to sit in the chair again, these symptoms escalate throughout the later stages; Stage 2- visual hallucinations, i.e., believing other chairs to be the chair; Stage 3- the chair begins to move, as if being pushed along the floor by an unseen force; Stage 4- chair is able to trans-locate itself with any other object within the field of view of the afflicted person that is perceived to be a chair. chair continues to move autonomously; Stage 5- chair will assume a standing posture and actively pursue the afflicted person as though it were a bipedal organism, attempting to grab them from behind to force them to sit on them.
Gravity Control Device: basically a handle with a trigger, a button, a radial dial (like a radio tuner) and a suction cup: attach the suction cup to an object an press the button to turn off the object's gravity; pull the trigger to 'shoot' the object at a velocity determined by the position of the radial dial, or press the button again to re-apply the object's natural gravity.
The Facsimile: a generic looking, hairless, 'Ken-doll' humanoid with a completely tame personality, the intelligence of a chimp, and a body that is completely indestructible: flesh is made of a material that is flexible under low tension, and harder than diamond under high tension, e.g., squishy if you squeeze it with your hands, but if you hit him with a hammer, you'll only damage the hammer.