Hmmm I like both to be honest but if I had to choose I’d probably go for cats and dogs. I love Brindleton Bay, it is one of my favorite worlds behind Windenberg. The pets are really fun to watch and interact with. I personally love that you can’t control them or see their needs, to me that is very realistic to a real pet. They do a lot of really humorous things that you don’t expect because you can’t control them. The CAS is one of my favorite for male sims and the female stuff is pretty good too. The BB stuff is some of my most used out of all the packs. And as others have said create a pet is seriously incredible.
Now city living is great too though. I love having small families and single sims live in apartments. The world is really cool and each district is very distinct. The festivals are fun and the worst bug with them has been fixed with the latest patch so I plan on really using them again. The new careers are also all really fun. City living has a lot of new little things to do as well.
I think it depends on your play style for sure. Are you more of a family player or do you play a lot of single sims? I’d say CD for family player and CL for single sims. Also I just recently completed my collection after not being able to play for over a year. I watched reviews of the packs to help me or Let’s plays. It helps a lot to really see what’s in each pack.