Your art is gorgeous, I especially love the way you draw guys. It's stylish without being overdone, and you use gradients pretty tastefully as well. You don't see a lot of people doing monster art for MMOs, either, unless they're the mascots or the near-human types, so good job on those too!
This sounds like a weird piece of praise, but you depict actual... volume, weight, and occupation of space pretty well. Between your weighted lines and the way you use color and light/shadow (think the last picture in your original post as the best example of what I'm talking about, especially the fur detailing) to suggest bulk... I don't know. It's something you pull off even in your sketches, and brings life to your work without any hint photorealism. Back to the gradients, too, I like that you apply them to enhance the lighting of a picture rather than replace it. I've seen the latter far too often.