Nos. 1 and 2 aren't exciting - that's true. There is no foreground to lead your eye from the bottom (front) smoothly to the background (top).
Nos. 3, 4, and 5 are a different story - very nice. They have a foreground, and mid-ground and background (albeit not terribly far back for 4 and 5).
No. 3 has the elements of a good landscape image.
Tim Fitzharris recommends the following approach in his book on landscape photography:
"The relative size of landscape features is one of the most obvious cues in conveying the depth of a scene. Objects that are closer appear larger than those that are far."
"Lens focal length generates a powerful perspective effect. By emphasizing the different size cues, wide-angle lenses increase the perceived distance between elements in the composition and promote a feeling of deep space."
"Because the eyes of a standing human are some 5 or 6 feet above the ground, landscape features that are close to us are positioned lower in our field of view than those more distant. For a maximum three-dimensional effect, you should set up at about a 45 degree angle (above horizontal) on the first cue size in the composition".
In other words, the lowest cue or feature in the picture that gives us some sense of scale is what should be seen at a 45 degree angle down from the lens (the closest feature), and it should be in focus. This is one reason that No.3 shines above the rest (and the subject is good too).
I've learned more from his book than from all other sources combined.
http://www.amazon.com …ext_b/102-9762121-5311311