| 3 × | exploration |
| 3 × | investigation |
| 3 × | controversy |
| 3 × | drugs |
| 3 × | disaster |
| 3 × | bbc |
| 3 × | conspiracy-theories |
| 3 × | illuminati |
| 3 × | environment |
| 3 × | disease |
| 3 × | experience |
| 3 × | genius |
| 3 × | louis-theroux |
| 3 × | terrorism |
| 2 × | alien |
| 2 × | astronomy |
| 2 × | universe |
| 2 × | culture |
| 2 × | development |
| 2 × | church |
| 2 × | sexuality |
| 2 × | business |
| 2 × | industry |
| 2 × | evolution |
| 2 × | tragedy |
| 2 × | inspirational |
| 2 × | nba |
| 2 × | career |
| 2 × | civilization |
| 2 × | christianity |