I'm in agreement with Samanax
#1 not liking this one too much. I get the artistic attempt, but really it just looks odd and looks like something taken while driving
#2 The composition is nice and nice job on the exposure / silhouette. But yeah, the tree is not in focus which ruins the image. When working with silhouettes, it is so key to get them in good focus (for me anyways). As we don't see any other detail in the silhouette, getting the shape and edges blurry is distracting.
Try shooting with a tripod to ensure a sharper image at low shutter speeds.
#3 cute picture but it has very dark colouring. Try a levels adjustement in photoshop and maybe a slight colour saturation. Shooting through a tank can sometimes cause image blandness. Make sure the tank is clean too
#4 not into this shot. there is not too much interesting going on. While regular subjects can be interesting if you play with their lines and angles, this one doesn't do that. If you were trying to play wtih the lines, then don't have the lamp in there as its brightness draws my eye and i dont pay attention to the rest.