Okay, CnC time, sorry it took so long:
1st sig: First off, the rainbow design on and around his arm really ruins the simplicity of the sig for me, it kinda looks like it's just.... there :/ The C4D on his shoulder is kinda nice, the splatters are nice.
The only thing that really irks me is the planets/stars/lights/whatever on the left side, I guess they kinda go with the theme since there's a Darth Vader helmet on the stock but I think it kinda takes away from the brown background. Text is nice.... and funny, good font.
2nd sig: It bores me, the lighting's good and the splatters are okay but the background makes me yawn, it's too simple if you know what I mean. It could use a little cropping done to the left side if you aren't gonna do something with the nega-space.