Corbuzier's Free Will - Perfect for walk around.
@RickEverhart recommended it to me and I know he uses a lot in his walkaround sets.
You Pick My Card in Kirk Charles's Hidden in Plain Sight is one that stumps spectators. You need a gimmicked deck which should be obvious is you look at any description of the book.
Rich Ferguson's This is Mentalism has some great stuff that works close-up or for a stand-up performance including Alpha Pack and Security. He also teaches the
TOXIC calculator force can be used close-up.
Anything in Max Maven's Prism is gold. You will pick up several pieces of great mentalism in that book.
If you want to find stuff that nobody else is performing, download all of the issues of The Jinx from lybrary.com or the Conjuring Arts Research Center.