Karlstad Sofa - $599
It has my three top criteria in sofas:
1.) Clean lines
2.) SLIPCOVER! (with a dog in the house who knows no boundaries, couches are the first thing to get ruined... I love the fact with this sofa I could take off the cover and bleach the heck out of it.)
3.) Inexpensive (as I stated in criteria #2, no matter how cheap or expensive our sofa is, it will get abused. I cringe at our current sofa knowing that it's a Thomasville and the in-laws paid a pretty penny for it.)
Added bonus: I sat on this sofa at Ikea the other day, and it's actually comfortable, too!