I'll admit my favorite couple is

why

• I think this is one of Yesung's favorite bandmate besides RW; Yesung gets mad when Eunhyuk doesn't visit his room (and he visits Eunhyuk's)
  
• Eunhyuk accepts his friend's weirdness
• friendship is unique and special
• YS takes very good care of EH
• they complement: YS is one of the best singer; EH is the best dancer
• They're just funny together
• This is the funny part: Whenever YS writes on EH's cyworld, he calls himself "Poppin' Kim jonghoon (his actual korean name)" (he wants to prove to EH that is also a great Poppin dancer like Eunhyuk). YS comments on EH's cyworld a lot.
• EH got a chance to watch his hyung in Hong Gil Dong.