either they mean something cool, are fun to say, or both :D

• cadaverous
• conundrum
• doppelganger
• eclectic
• empyrean
• epiphany
• facetious
• glamor
• gorgeous
• inordinate/inordinately
• mandible
• palindrome
  • (and words that are palindromes are pretty cool too)
• panache
• phantasmagoria
• shenanigans
• splendor
• surreptitious
• swagger
• tremulous
• vacuous