First, A Brief History...
In the original Trek
canon, Khan Noonien Singh (Ricardo Montalban) was an Indian superhuman during Earth's Eugenics Wars in the 1990s (the episode was shot in 1967, just roll with it). Endowed with superhuman abilities and intellect, he and about 90 other genetically enhanced humans declared war on all inferior beings and attempted world domination. When this failed, Khan and his men escaped on the S.S. Botany Bay
and placed themselves in cryogenic freeze, and Khan and 72 of his men would be woken up 300 years later by Captain James T. Kirk. After they attempted to take over the ship and set their sights on galactic conquest, Kirk sentenced Khan, his men and a traitorous Lieutenant to life in exile on Ceti Alpha V. Flash forward 15 years: Chekhov, now first officer of the science vessel Reliant
, is sent by Dr. Carol Marcus to Ceti Alpha VI as part of a large scale terraforming project known as Genesis. But, whoops, Chekhov and his Captain don't realize that this is in fact Ceti Alpha V, and they beam down right next to Khan and his men's lair. Discovering that this Genesis could be utilized as a weapon of mass destruction, Khan forces Chekhov and Captain Terrell to lead him to Kirk where he will steal Genesis and use its ultimate power to kill Kirk and destroy the Enterprise
. The Enterprise
defeats Khan, but as Spock Prime recalls in the new movie, "at great cost," Spock's life. In the reboot universe, Khan Noonien Singh is instead awoken by Admiral Alexander Marcus, the commander in chief of Starfleet immediately after the events of the previous film, notably the destruction of Vulcan. Marcus recruits Khan to Section 31 under the name of John Harrison as a human super weapon in the imminent Klingon war, but uses his 72 surviving comrades from the Botany Bay
as leverage, causing "Harrison" to defect and declare a one man war against Marcus and the Federation. "That being said, Khan Noonien Singh is the most dangerous adversary the
Enterprise ever faced. He is brilliant, ruthless and he will not hesitate to kill every single one of you." -Spock Prime
Same character, same history, different portrayals and very different outcomes. So... who wore it better? Ricardo or Benedict? Let's start with the two traits Spock Prime mentions in the above quote and work our way from there, shall we?