I like the way you got the guy to look the way he it. That shot looks really nice, the spikers are the perfect weapon for the picture
The spartan is in a cool position but overall it's nothing special or unique. The common explosion screenshots have been used before. Try to be a little more creative with the screenshots. Fool around in the game a little bit then go into theatre and go crazy and see what you can do. You may accidently find something you didn't try to do and it could be a great screenshot. Also your signature is too wide. Might wanna fix that.