50/3.5 for sure.
Ive heard nice things about the f2 version, Ill soon see first hand.
maybe some will post their shots from it, pretty please?
I posted a recent 50/2 shot a couple weeks back. My impression:
It's big. However, once I committed to having the 21/2 and 90/2, it fell in line with them.
It's sharp.
It's flexible (speed, distance)
It's bokeh isn't to my liking. OM Zuiko lens bokeh is not my favorite: it isn't as smooth as what I find elsewhere. However, the 50/3.5 may be different. I know the bokeh on my (fabulous) pen macro lens is great and I understand them to be siblings of one design.
If I were using lenses only on digital, it would be a no brainer - I would go slower. But if I want to shoot sakura on Velvia 50, there is no alternative to the 50/2. It does stuff the others cannot.
Here are a few sakura pictures that may illustrate the character of the 50/2 on Velvia.
Smooth
Getting rougher
Of course, where it is in focus, you KNOW it is in focus. Just sharp as all get out.
One last (and not particularly good) picture:
As I go through them I realize that it is the mid-distance background that is at issue. Far and near are fine as far as bokeh goes.
The 90/2 is awesome, but given the flexibility of the 50, it gets less play.
Edit: The above were all on OM-2n.