js wolf3d http://www.wolfenstein.com/game/wolf3d.html has the most awesome css spritesheets:
http://zmi-cdnstatic.s3.amazonaws.com/wolfenstein.bethsoft.com/art/bj. png
http://zmi-cdnstatic.s3.amazonaws.com/wolfenstein.bethsoft.com/art/wal ls-shaded/64/walls.png
http://zmi-cdnstatic.s3.amazonaws.com/wolfenstein.bethsoft.com/art/spr ites/128/002_053.png