I've had both over my life. Both have pros and cons.

As others have said, cats overall require less attention; both in interaction and maintenance. Our cats are really good about keeping house bugs to a minimum with their natural hunter instincts. Flies,moths and other critters don't last long. Also litter boxes are something I wish dogs could figure out lol.

Dogs are more social, so they'll need more from you. They need frequent outside time to run and exercise/bathroom. Most dogs don't care about catching bugs and critters like cats. However, if treated right, will defend the house to the death from intruders.

In my current situation, cats are better. If I had a much bigger, we'll fenced yard, I'd love to have a dog again.