If you have a fenced-in yard, you can have really and dog breed you want, but you might be on poop duty.
That's just part of having a dog. Being unable/unwilling to walk the dog is a huge part of the exercise. Generally, though, they'll be likely to do their business in corners or out of your sight. If you want a dog with few needs, just get a cat. However, if a dog is a must, small breeds that get tired easily like Shih Tzus, Pomeranians, and especially dachshunds.
You may love dogs, but may be unable to house one, especially with no fenced-in yard, and that's perfectly okay. You may be suited to house cats.
Generally, exercise is a must for a dogs health. Taking the time to walk may be too much, but at least half an hour needs to be taken out of your schedule to play with them no matter which breed. It's unfair to the dog if you can't offer that.