They're all nice, but I prefer #1 and #3. The log is a nice contrast to the rounded rocks and water and brings the eye from the top to the bottom of the frame
Nice composition, but my eyes are drawn directly to the log in the first one. It just doesn't look like it belongs at all, mainly because light is coming down and the log doesn't cause any shadows whatsoever. So that makes it very disturbing to me. I like the 2nd one the best.