[Vergil the Fallen]

well i can't judge a person until i know for how long he/she has been making sigs. If u are a beginner, then no one has the right to give u some harsh comments but if you have been making sigs for quite some time then harsh comments are understandable. But nevertheless i'll point out some defects.
The first one is too plain. There is no blending at all and the render and the bg do not compliment each other. Its like you created the background and then put on the render.
The second one has the same problem but is much worse. He did try to create a shading effect but failed. Again the renders are useless here.
The third one is extremely simple which means-> bad. No blending again, u just liquified the background and placed the render but thats it.
The last one is a complete mess. U just randomly applied stuff.

My opinion is take a look at some beginner tutorials online and from then you will learn how to make good sigs.