Oh boy. Inspiration is a big one and not something I can point out easily. A lot of my ideas are based off what I saw, thought was cool, and implemented. For my only active project, Lorithane, some of the inspirations off the top of my head are:
The idea itself came from the many Planes of Existence in D&D cosmology. Most planes around Lorithane are based off the Original D&D planes, and the idea that they're all interconnected and in frequent contact with each other. The MMO Rift executed this idea in gameplay, but I wanted to make some of these large interactions more permanent in Lorithane.
Dragon Age: I set my dwarves close to Dragon Age dwarves, being primarily underground (well, that is a lot of Dwarves isn't it) and the idea of them not carving out their tunnels (potentially), but finding them already there. I've moved away from a lot of the Dragon Age influence over time, however. A more recent inspiration would be a scene in Inquisition that inspired the idea of Demon Binding in some of the far reaches of the continent.
http://goblinpunch.blogspot.com/ supplied a lot of inspiration. They're a lot of non-traditional takes on traditional races in there. In particular, the idea that Elves consider themselves the pinnacle of beauty (and sometimes violent in an attempt to make others "beautiful") and Orcs having some form of blood worship originated from ideas there.
Warcraft inspired the Aseran and Violet Echos with the Outlands and Dranei. The idea of another, completely alien world being forced into another one interested me. In this sense the Corruptors (which I haven't dove into yet) are like the Burning Legion in a way, but less demonic and more undead + Lovecraftian.
And there is plenty more I can't recall.