This is honestly my favorite question to get asked, but it depends. Since you said "friend" I'm going to take the liberty of the fact that I know much more about them than I would a complete stranger; I really like to tailor the song choice to the individual, but I'll provide my most common recommendations. Context 23 year-old Black male who was responsible for the music at parties.
For a complete stranger: (Fleetwood Mac - The Chain)[https://www.youtube.com/watch?v=nKGuaN0Nt1c]
For a male friend that I know doesn't like rap or electronic music: (Childish Gambino - Bitch Look at Me Now (Two Weeks))[https://www.youtube.com/watch?v=CHYvFS9nEHU] or (This specific, explicit music video; Swedish House Mafia vs. Knife Party)[http://www.vevo.com/watch/swedish-house-mafia-vs-knife-party/antidote-(explicit)/GB1201100110]
For a female friend I know doesn't like rap or electronic music: (Emeli Sandé - Next to Me feat. Kendrick Lamar)[https://www.youtube.com/watch?v=DXIfnAcxiI8] or (Ummet Ozcan - Lose Control)[https://www.youtube.com/watch?v=HK1fZ0GLj3o]
For a friend who loves rap: (The Prodigy - Breath (Zeds Dead Remix))[https://www.youtube.com/watch?v=plLaK4QWKdE&index=17&list=PLjGLtb4L38TRhlpHy_zbFqmDaM3kj0WVq] or (ZZ Ward - Til The Casket Drops (this song and the whole album))[https://www.youtube.com/watch?v=EmEdyFIi-n4]
For a friend who loves electronic: (Tool - Parabol + Parabola)[https://www.youtube.com/watch?v=9vluBFWv4mE]
For the single ladies: (Ferreck Dawn - Superman)[https://www.youtube.com/watch?v=SujRYXA5OLU]
For myself: (Corey Hart - Sunglasses at Night)[https://www.youtube.com/watch?v=X2LTL8KgKv8]
Yes, I specifically would show people music in genres that they would be reluctant to try.