They all have some interest. Some of my random thoughts as I looked at them.
I like the DOF in the first one.
I would have included more of the orange car (shot lower).
The bird seems too centered. I would shoot that one with the bird more to the right in the frame, giving him more space to look into, and maybe zoom in a hint.
The colors are nice on that last one. It looks somewhat challenging because the point of focus appears to be in sunlight, while the rest is in shadow. I might have tried shooting more from the right (if you can without falling off a dock or something) looking down the chain so mostly chain and blue boat are in the image and not the items in the background left. This is a situation where a few different things could work, that's just one idea. If you had something to block and diffuse the sun on the link where the focus is that might be ideal, or fill flash on the rest of the chain (if wireless flash is an option).