User blog comment:Bobdave/Epic Rap Battles - Modern vs Classic. Mark Zuckerberg vs Alexander Graham Bell/@comment-6533831-20160715010019

Some other ideas I thought of

Superman (Classic) VS One Punch Man (Modern) (Powerful Superheroes)

George Washington VS Barack Obama (or whoever will be president by 2016) (US Presidents)

George Lucas and Roddenbury (Classic Star Trek and Star Wars) VS JJ Abrhams (New Star Trek and Star Wars) (The Original Creators VS The New Director Taking Over)

Ed Sullivan VS Jimmy Fallon (Late Night Show Hosts)