Credit: Getty Images

Best for: Companion-seekers with lots of acreage, a high fence and a tolerance for (near constant) vocal feedback.

Even-tempered, spirited, and healthy, beagles are one of the most popular breeds. Their superior sense of smell sends them darting after other animals, so keep yours on a leash or in a fenced yard. Their downside: a Mariah Carey-like vocal range that produces several distinct howls and barks. Ample attention can alleviate this problem, but if you're gone all day, it may perform an aria for your neighbors.