Excluding numbers 9 (Van Buren) through 25 (McKinley), who's the most forgettable president?

The 3 that really stick out to me are

  1. James Madison
  2. Calvin Coolidge
  3. Gerald Ford

To a somewhat lesser extent, HW Bush was also pretty forgettable.

Edit: I have been informed that Van Buren was actually the 8th president. But I can't edit the thread title. So exclude presidents 8 through 25.