4Chan

Im sure you have heard of the website called 4Chan. Its an image board with various sub-topics. I frequently visit 4chan, and mostly go on /g/ Technology , /k/ Weapons , /v/ Video games , and /m/ mecha or robots. Each board has its own set of rules and regulations, with daily events( if you're into those things).

There are a lot of cool images on this site that are pulled from other sites and sometimes handmade by the posters themselves. Here some I thought were cool:

Some sort of GN Prototype from Gundam 00

/m/ related images

Heavy Arms Ver. Kai
Gundam Wing Endless Waltz

M8 Gernsback
Full-Metal Panic

Astevalis Ground Frame Akito
Martian Successor Nadesico

Its a really cool website. Just be careful where you go. There are some adult images and topics on 4chan, and some of the material there may offend people.