The Spidey one is from "Renew Your Vows" run, don't remember the issue number.
Superman is from Dan Mora Chaves inspired by the trailer launch for the new Supes movie.
My current desktop wallpaper & a quick 'Ink Sketch' edit of it I did on Photoshop because my monitor's contrast is ass and I couldn't read folder names with the original being the background lol.