Wow... Those are nice. ^_^ I like the top one best. Batman one's a bit oversharp. Very cool. Maybe a bit more detail in the BGs, but they're still nice.
first one looks better for me. dark sig is good for batman but is too dark and effects are not good visible, it's too plain. nice style in both sigs
1st: Nice composition, and some nice effects, but i think the color could use some work. i'd make it more of the color of his tie. some nice stuff though! 2nd: Way too messy i think. the splatter effects are over-sharpened i think. like the lighting, though. nice touch. I agree with some more detail in the BG, but sometimes there are tags that are good with some simple BG's, and I think these are an example of that. Very nice job!