The antonyms for "most off the wall" would be "conventional," "traditional," "mainstream," "ordinary," and "typical." While "most off the wall" indicates something that is out of the ordinary, unique or bizarre, the antonyms suggest something that is conservative, conformist, common, usual, and ordinary. They describe things that are within the parameters of what is expected and accepted by society or the mainstream. In contrast, "most off the wall" implies something that goes against the norm, challenges conventions and expectations, and is unpredictable.