Tell your friend this is a dangerous game to play..... Along with a few friends I got married last year... My friends all asked for suggestions then had an evening do playing people's requests in a certain order with no one on the dance floor as it was so random!! I on the other hand let the DJ get on with it (after all that's their job!) and he chose songs to get people going and was brilliant!! What people like when they are stone cold sober is different to when drunk!! Sorry that's not very helpful
But if you need a suggestion... Don't forget "oops upside your head" for later in the evening!
We added a line onto our RSVP asking guests for the one song that was guaranteed to get them on the dance floor. I think we must have been lucky as everything seemed to flow quite nicely into styles. We had a massive wedding, so there was no way everyone's song would be played. We just gave the selection to the DJ and let him choose.