Depends on your bike and style of riding.

People who have a bike with drop bars and have their bars set at or slightly below saddle height, will want a tapered, moderate fitting saddle. In the Brooks line, that would be a B-17/Flyer.

People who have a bike with flat or upright bars and have their bars set at or above saddle height will want a wide saddle so they sit on it with their rear end on the saddle. In the Brooks line, that would be a B-66/B-67/B-73 and B-133.

Saddle choice is personal and reflects your riding style and comfort preferences.