You got some impressive stuff in here, I really like your sig work, most have a unique feel to em, you seem to have a good sense of composition, my fav is your bioshock sig. The drawings are pretty impressive too, love the wow char's, and I really like that girl with the scythe. I think you should put some more time into these, I wanna see more like them.
btw, I like these sig's with different screens in different area's but try to keep all the images sharp in them, if you're using stock that is pretty much flat colours, a few of the right filters before and after resizing would really helping. If you're using stock that doesn't use flat colours, make sure you use as high res stock as you can get your hands on.