i have a similar site. can i use your wallpaper(i am not edit your wallpapers logo or etc.) if you think sharing and make more visitors then please agree. i will give you a permanent link.
color: too dark.more shiny will be better. Categorize your wallpaper for easier search. Overall i give 7/10 score for your website.
I love the header and the black background works well with the colorful images. Your copyright could use a lighter font for readability.