I mostly follow the official one on Scala. I deviate from it a little to help me stay sane when switching between languages like 4 spaces tabbing and sticking to K&R style[1] for indentation/braces. Using an IDE like Intellij or Eclipse can also help reinforce consistency as well since you can set the way it formats for you (and also have it auto-format before you commit to git).
Most important thing is to just stay consistent with whatever you decide upon more than which formal style you choose. If I were working in a team with Scala, then I would stick with a formal spec (or just let the IDE auto-format for me to adhere to the team's style when committing).
Google returns this: http://docs.scala-lang.org/style/ or this: http://davetron5000.github.io/scala-style/index.html but do you have any that you'd recommend?