I love Garchomp C Lv. X from the pack. There is a reason I made it my avatar, and that is because it looks plain awesome. I like it with a black background, and I think it looks cooler with red eyes instead of yellow (both details were put in to my avatar with Photoshop.) Garchomp looks like it is running out of the card to attack a player, which it does really well with Dragon Rush.
Someone posted an image of it on Page 1 of this thread, but my avatar is also the artwork of Garchomp C Lv. X.