Lost has many episodes that continue to be celebrated, but there are also underrated episodes that deserve to be talked about more. “The Constant” is widely considered to not only be one of Lost‘s best episodes, but is also hailed as one of the best episodes of television that has ever been made. It features a brilliant use of time travel for the deeply emotional love story between Desmond Hume (Henry Ian Cusick) and Penny Widmore (Sonya Walger).