To be fair I haven't yet seen "John Dies at the End" so there isn't much competition in this category. The only other contender is "Eddie & the Cruisers 2: Eddie Lives" (which spoils 2 movies in the title so it gets bonus points).

But wow, for a movie that spoils the ending in the title, this is one suspenseful ride! Gotta love the 50s-60 French filmmakers Robert Bresson, Henri Georges Cluzot and Francois Truffaut who studied Hitchcock's playbook and went the extra mile. My fave is probably Cluzot ("Diabolique", "Wages of Fear") because there's a lot of energy in his films, keeping them entertaining as well as suspenseful. Bresson seems to be paced a bit slower, more methodical and scientific, so his suspense builds up without any release until the end. Can be kinda stressful, so I prefer Cluzot's/Hitchcock's style of giving us occasional relief. All the same, it takes a true master to keep the suspense going for nearly 2 hours without a break. The title is the only "relief" we get. Makes me wonder if that was deliberate to avoid any heart attacks in the audience.