| In this series, E! lists 101 of the most significant moments in certain aspects of entertainment, from celebrity couplings to major public gaffes. Actors, comedians and "experts" from the field of entertainment provide commentary throughout each countdown. Each countdown takes place over the course of five nights. |
| Name | Character | Episodes |
|---|---|---|
| Joel McHale | Self | 65 |
| Chad Doreck | Self | 65 |
| Andy Milder | Self | 65 |
| Tom Arnold | Self | 4 |
| Larry Miller | Self | 4 |
| Carmen Electra | Self | 4 |
| Stephen Furst | Self | 4 |
| Rachael Harris | Self | 3 |
| Beverley Mitchell | Self | 3 |
| Mathew St. Patrick | Self | 3 |
| Simon Cowell | Self | 3 |
| Omarosa Manigault | Self | 3 |
| Greg Fitzsimmons | Self | 3 |
| Randy Jackson | Self | 3 |
| Jay Mohr | Self | 2 |
| Jack Wagner | Self | 2 |
| Ed McMahon | Self | 2 |
| Brian Thomas Smith | Self | 2 |
| Justin Guarini | Self | 2 |
| Ereka Vetrini | Self | 2 |
| Mary Steenburgen | Self | 1 |
| Seth Green | Self | 1 |
| Jim Belushi | Self | 1 |
| Lance Bass | Self | 1 |
| Steven Weber | Self | 1 |
| Patrick Warburton | Self | 1 |
| Lake Bell | Self | 1 |
| Holland Taylor | Self | 1 |
| Tyra Banks | Self | 1 |
| Christopher Knight | Self | 1 |
| Karen Lynn Gorney | Self | 1 |
| Mark Curry | Self | 1 |