Um, I bet just about any color would work just fine...what colors do you like? Other than white I mean :>

You could really take advantage of all the neutrals and go wild with the rug. Something with a bold, colorful pattern could have a big impact.

I'm pretty sure that any colour in the world will match white, ivory, and stainless steel. Either go with another shade of white for that oppressive 'Sleeper' feel, or get absolutely any colour you want: pale to keep it calm, red or orange or pink to warm it up, blue or green to make it even cooler. Your choices are limitless - just choose what you like.

I agree with Lisa, I think a graphic black and white is PERFECT!! kinda like the manuscript rug I've been seeing a lot lately...

http://www.cb2.com/family.aspx?c=170&f=3928

(I know there's a $$$ on DWR but I like this one better)

again, I'm a color fan. You have so much neutral and sparse that you could go with any color that comes to mind. With the chocolate coffee table you could do the trite (but lovely) ice blue, or you could go retro-modern with burnt orange, fresh with avocado/wasabi green, bold with red, mod with graphic brown and white

How about something like this? I could move in here tomorrow...

http://www.hgtv.com/hgtv/dc_design_living_area/article/0,1793,HGTV_3376_5679614_02,00.html

red, red red! or just about any bold color will work.

I love bold rugs, I have one myself. For this room, I would recommend a rug with some color, but muted rather than bold. How does this strike you?

http://www.roomandboard.com/rnb/collection.do?method=get&id=377968&cat=91

Go grey. Modern and elegant.

I'd go with a black and gray tone-on-tone pattern.

Please tell me there's interesting art or a mirror or something on the wall though.