A guy called SmashMethod has made some awesome wallpapers and stuuf based on Mario games heres some of his work!
As The Sun Sets On Mushroom.......
A Very Shy Gathering
Mario Love 6
Link to SmashMethod's DeviantART Profile and gallery:
Mario Love 4 (My personal fave and wallpaper)
Mario Love 2
Those are pretty cool, probably better than anything I could do!