Some of the larger livestock guarding dogs, like Great Pyrenees and Old English sheepdogs, are relatively low energy. Given walking to get the out and exercised, they're OK with sitting around, so they actually make better apartment dogs, in my opinion.
Various friends of mine have retired/rescued greyhounds, and from what I've seen they're very docile and low-energy indoors. They are big, but they just want a couch to lounge on and someone petting them.
I agree re: little dogs. Also, people tend to under-train...well, dogs in general, but little dogs in particular. Little dogs get away with aggressive, dominant behavior that would be instantly unacceptable in a larger dog. Jumping on people, for example. Little dogs get "tee hee, he thinks he's big". Huge disservice to the dog, who just needs to know who's the leader.