While sisal rugs are N#1 for me , I also like rugs with geometric motif. Here is a small selection from my inspiration file.
Photo Pamplemousse design
Photos David Kleinberg Design
Photo Ashley Whittaker 
Photo Katie Did Blog
Photos Timothy Whealon
Kelly Wearstler
Photo Nate Berkus
Photo Thad Hayes
Photo Sara Story Design
Photo Diamond Baratta. Love this tiles floor color combination
Photo Jonathan Adler 
Photo Katie Leede
Photo Pamplemousse design
Photos David Kleinberg Design
Photo Ashley Whittaker Photo Katie Did Blog
Kelly WearstlerPhoto Nate BerkusPhoto Thad Hayes