All wonderful images, but I'm going to go with no 3 as my favourite, then 4, then 2 and then 1.
No 3 has direct, reflected and filtered light in the one shot, and therefore captures the differing lights found in a wood perfectly. There is something about light being filtered through leaves that gives an image an indefinable something. I always find filtered light peaceful and the green glow of filtered woodland light is so calming. The other thing that draws me to the image is the relative lack of scale/height. Despite it too being shot in portrait it lacks the height of the others, and seems to suggest a lower, almost voyeuristic view of the wood. This is assisted by the two trees framing the image and the shallow depth of field. You can see the image has depth, but you can't quite make it out what's back there which gives it an intriguing quality. I was put in mind of a very dark and dense woodland, with just this one patch of light reaching the ground, almost like an oasis in the gloom. Great contrast, wonderful light, and a certain something that drew me to it.
No 4 I like because of the way my eye was drawn around the image. The intense sunlight in the lower left of the image grabbed my eye, which was then drawn up the reflected, almost translucent light on the thin branches of the tree above it. I found myself wanting to look up further into the source of the light, and the fact that I couldn't was great, because I then found myself looking to the left then right at the different but bright shades of green in an otherwise low key image. Finally my eye was drawn back down to the smaller patch of bright sunlight in the lower right corner. At first glance I thought that I would personally have cropped a little tighter on the left side of the image as my eyes did not find their way there, or see any detail once I looked closer, but when I thought about it again, cropping this section out would have moved the silhouetted trees more central losing the overall balance of the image.
Nos 2 and 1 did less for me, although, that said, I still like the images, and in particular the contrast within them. I agree with the others that the lens flare is not a problem, and would even venture that it is a benefit to both images. You have a line of trees leading from bottom left to top right drawing your eye into the image, and this is nicely countered with the lens flare going across the image the other way. The sun is a key focal point in both images, and could dominate and overshadow the rest, but the lens flare (IMO) draws your eye away and back into the shot. No 2 shaded it over no 1, because the higher aperture used has kept the sun more compact, reducing the number of emanating rays. It remains a focal part of the image, but is less distracting or dominating than in no 1.
Nice shots LaFoto, I would love to see more, that is if you can put up with my subjective ramblings!
David