Would need to know more to be 100% sure, but I personally am a fan of #2, but perhaps with more line spacing as in example #1. I'd also see #4 as a good alternative, depending on the style of the work.

I think # 5 is too far spread out; generous spacing is good, but it'd evoke high-school essays for me, and # 3 feels too tight. #1 would be okay, but I just prefer the font of #2 a little more in terms of size.