I just had to reply to this. First vip-ip and admans are right and secondly the people here are really nice, I mean really nice.
To be honest in my opinion they aren't really good. The only one that is half way decent is the last one logo 8 but the grain filter doesn't look good. To make a nice wallpaper you need to :1. do what vip-ip and admans said and 2. put a lot more thought into the design.
Think about where you want the viewers focus to be and make everything compliment it, choose colors that compliment each other, also sometimes less is more, a busy background can make the wallpaper look bad. I could go one but it's late and that is a very good start for now.