Being two of the premier heroes in the DC Universe, it would be expected that the battle taking place in Batman V Superman: Dawn of Justice would incite other heroes to choose sides.
That's exactly what the cast of CW's The Flash has done, and it looks like Superman's getting a lot of love. Danielle Panabaker (Caitlin Snow), Grant Gustin (Barry Allen/The Flash), Carlos Valdes (Cisco Ramon), and Jesse L Martin (Joe West) all took Superman's side, though Carlos only took it because Superman was the sexier of the two, so in Batman's defence I don't think that should count as a full vote.
The Dark Knight does have his supporters, however, as Candice Patton (Iris West) and Keiynan Lonsdale (Wally West) represented Bruce Wayne pretty well, and confirmed what we all know.
Batman wins, hands down.