Good call. Whoa – this is cool:
And you can pick up on it with a chrome chandelier.
Also wall decals:
http://www.allposters.com/-st/Abstract-Wall-Decals-Posters_c139269_.htm
Or a nice Rembrandt.
Oooh. Liking the Mondrian.
How about an American Diner theme? I’ve seen photographs, sketches, paintings, of some cool stuff all Diner related that could be pretty engaging all put together.
Damn, so many great ideas. Now I don’t know which one to choose! 
Pictures of other people eating food
Also, are there any windows in the space? I am guessing no but just checking! Even without windows, you could do a fabric wall to soften up the room and add some texture.
You could always go in a completely different direction. Here’s an oil I was considering the other day (before the little missus turned up her nose), the contents of an old, dilapadated shed, although very well done. You could find one of… I know, a bunch of dirty dishes piled up in the sink. It sure wouldn’t be “cliche.” 'Course with something like this it really helps if you’re a bachelor.
Women!
A friend of mine altered a couple of prints, a little subtly. A street scene of Paris has a tiny UFO flying overhead, and a scene of the canals of Venice has a Loch Ness Monster floating along in the background.
Customizing is fun!
Yeah! I once saw someone’s work. They took uninteresting landscape paintings from Goodwill and added Godzilla or similar monsters. Man, I wish I could paint. I’d be all over that.
You are talking to a mostly-Dutch girl with a degree in animal physiology, so yes, I would totally put that on my dining room wall.
I am the artful voyeur
Of your brain’s exposed and darkened combs
Your muscle’s webbing
And all your numbered bones
–Seamus Heaney
I’ve always wanted to hang a wall-size copy of Guernica in a dining room, facing the guests’ seats. 
But, if you’ve got a classic gaming bent, you might try some Georges Seurat instead.
For a more offbeat yet still pleasant look, there’s the works of illustrator N.C. Wyeth, although those might be better suited for a room with a fireplace. Perhaps a study, parlour room, or drawing room (the Conservatory and Spicery are, it almost goes without saying, probably unsuitable).
Dogs playing poker or Elvis on velvet…
OK I have some famous Australian prints on the wall from Norman Lindsay, very beautiful and a little bit risque!
Get some shadowboxes, and fill them with collections.
Stamps, antique toys, old perfume bottles sans labels, etc.
Odd shaped bottles, filled with colored fluids
Japanese prints always look classy.
This one is perfect.
This one!
How about kitchen tools on the wall? Like pots and pans, bowls, wooden spoons, etc.
Combine with this.
