1. PS4
2. The small teams means I feel like I have more of an impact towards success/failure. Also, the gameplay puts fun over realism, which is a refreshing change from my standard FPS games. Lastly, all character types are fun to play!
3. Roadhog, Mei, and I'm planning on mastering Tracer, because I love her playstyle. For Support, I'm leaning heavy towards Mercy these days. That Ult so good.
4. Stacked teams. I don't think they're fun to play in, or against. In my experience, it seems to happen more often with defense characters (stacked Torbs or Bastions).