I tend to agree with JohnnyBlack - the top right is the best of the bunch. Not even sure what the bottom two are. Also agree with the watermark - it is okay to have one, but it should never distract from your image. As JB has suggested, put it in the lower right corner - nothing wrong with lower left corner either. Just so you know - if you are thinking that a watermark will stop folks "stealing" your images - it won't. If I wanted one of your pics, it would take me less that 2 minutes to remove it, the watermark, in either Lightroom or Photoshop, but rest assured, I am not someone who does that sort of thing - take other folks pics.
WesternGuy