In theory, a William Shatner cover of Cee-Lo Green's massive summer hit "F*** You" should be a huge win all around. Shatner is famous for his unique takes on hits like The Beatles' 'Lucy in The Sky with Diamonds' and Pulp's 'Common People,' and Cee-Lo's song burned up the internet this summer before it ever hit mainstream radio.

Plus Shatner kicked ass with his dramatic reading of Sarah Palin's farewell speech and his duet with a Taiwanese reality show star. So Shatner's Cee-Lo cover -- performed live on Lopez Tonight -- could have been legendary.

Unfortunately, our beloved Shat looked and sounded like he was on something prescription-strength (or just having a really rough night). He barely knew the words, and he looked like he hardly knew why he was onstage.

Is this the same guy who belted out "Total Eclipse of the Heart" with Taiwanese wunderkind Lin Yu Chun just a few short months ago? Bill isn't as young as he used to be, so perhaps he's worn out from his work on TV's "Sh*t My Dad Says."

Whatever the cause, we'd rather not focus on Shatner's musical decline -- or, heaven forbid, the end of the Shatner cover as an internet trend -- so we're counterbalancing Shatner's worst cover with five of his best. Check 'em all out below.

F**k You





Lucy in the Sky With Diamonds (1968)





Common People (2004)





The Real Slim Shady (on Futurama) (2002)





Total Eclipse of the Heart (2010)




Rocket Man (1978)