Awesome
An image with a long, murky history with 4chan and Something Awful. Popular with probably every board, including /tg/.
If someone replies to your post with this image attached, he is essentially saying something along the lines of "fuck you" or "you're a fucking retard". This person is probably correct, since the purpose of /tg/ is /to generate/ RAGE.
External Links
ED's awesome article, featuring XBAWKS HEUG gallery of Awesome mutations
Gallery
<gallery> Image:Awesome.png|Standard awesome image. If you don't know what it means, gb2/gaia/ Image:Awesomecat.jpg|Awesome is back, IN CAT FORM!