Ok I just would like to know what program you use to help me give you some tips later on..
#1. I think this is your best one although it could still go with a bit of work. I like how you put Lucario over an image of space or something then the C4D's and fractals in between. This is a good way to add effects to a banner although sometimes they can look a bit choppy and distracting. You have done this reasonably well although I think you could use some which compliment flow better. The render of Lucario should be blended in a bit more. Try smudging or placing some brushes or effects around the edges and over the top to make it look like it is inside the image, not just placed on top.
#2. I see this banner having some potential, you just need to finish it off. A lot of the same principals apply for your banners so I won't repeat them in as much detail.. The banner is starting off well, all you need is some more effects, some C4D's and it will be finished. It is good to see you placing C4D's over the render which is good although I think it may be a bit much. Try erasing some of it over Ho-Oh's body and especially head.
#3. Ok, like the Ho-Oh one, it needs a lot more stuff to fill the empty space on the right. You covered the render heaps in this one which needs to be fixed..
On all of them, the text needs some re-jigging. It is very plain and kinda boring. Play around with fonts and colours until it looks good. Also try downloading some from DaFont.com..