Once more, into the breach!
My preferences:
Giant mechas. Gundam-ish super robot designs are fine, as are more realistic industrial-looking machines of war.
Knights! Detailed, shiny plate armor, preferably more fantastic and less realistic. (No boobplate though please. Female armor ought to be as decent as a male's armor would be.)
Pokemon-like 'upgrade paths' for a character design.
Fantastic landscapes- scifi or fantasy.
Interesting skyscapes at any time of day. Midday, sunset, starscapes at night, whatever.
Portraits/full-body sprites.
Organic designs- no cubism plz
Painterly techniques, with a focus on cluster technique, rather than fill-in-the-lineart works.
Videogame mockups, with a slight preference for top-down tactical stuff.
Above all else, I want to see pieces of art which would stand on their own merits, rather than attempting to smash every single thing I listed above into a single picture for the lolz. Make something that you would think is cool!