John-
I'm always hesitant to recommend my breed to people right off the bat (they're definitely not for everyone), but Shiba Inus are one of the world's best apartment dogs. They are a national treasure of Japan, and the most popular dog there. (Space is at a premium in their home country).
They rarely bark, yet they're naturally protective. They are incredibly clean, being almost cat-like in their habits. If it wasn't for the fact that I show my dogs, I could honestly get away with bathing them about 4 times a year. They don't have doggie odor.
However, they blow coat twice a year (and it's a lot of coat to deal with... you'd be surprised at how much a small dog can shed!), and they are a dog-aggressive breed. They need to be socialized early on, and training needs to be positive and fun. They're brilliant dogs- sometimes smarter than is good for them...
You can see a photo of my bitch in my avatar, and her son at 6 months of age in my signature. They definitely have a big dog look, in a compact body. (When I was searching for a breed, I absolutely wanted an animal that had a "big" look to it- I wasn't interested in a toy breed). If you're interested in more information, let me know or send me a PM, and I can help you figure out if Shibas work for you.
The others have also given some great ideas to help you with your search. Good luck!