I'm a fan of biddable breeds who enjoy working with their people, but prefer to keep it on a more chill level than, say, a border collie. I'm already a high-strung person, so having a high-strung dog on top of that isn't always the best combination. For allergy reasons, I have a strong preference for no/low shedding breeds. I know 100% hypoallergenic is a myth, but curly dogs are definitely kinder to my respiration than other coat types. I have a personal nightmare of having an emergency situation on a hike or when I'm home alone, so a dog small enough that I could carry and, if necessary, bike to the vets, is something I prefer. We may have a giant breed some day, but I want us to have at least two vehicles by then so we're less likely to get stranded.
My boys right now are lovely. Samwise is a little on the high-strung/excitable side of things, but I could absolutely see us having another poodle of any size some day. Frodo's only 5 months, so I haven't lived with an adult Lagotto yet, but so far he's a great match for us. Affectionate and clever, but eager to engage and train. And more level-headed than Sam... usually (he is a puppy, after all).
Other breeds I've considered are smooth collies, chinese cresteds (including powderpuffs), cirneco dell'etna (an oddball breed but I fell in love), some of the pinschers (esp. German Pinscher), a smattering of terriers (rat, fox, Airedale when I'm feeling brave), and saluki. I could see a staffie some day too. But a lot of these are more 'daydream' than likely to become reality any time soon, and I've put very little research into the details. Dachshunds and Leonbergers are also on the list, but that's because my wife grew up with the breeds and adores them (and I admit that the ones my in-laws have are absolutely charming).
I'm not a spitz person. They're gorgeous dogs, and I've met plenty I adore, but it's just not a temperament I see myself living with, barring a couple breeds that have a less 'spitz-y' personality if I absolutely had to choose one. Also the fluff, but there's ways to make that manageable if I really felt the need to own one. I also can't do breeds that have SUCH prevalent, extreme health issues that they're almost impossible to avoid - think Cavalier King Charles or English Bulldogs. Both for financial reasons and - more importantly - mental health reasons. Of course getting a special needs and/or short lived dog can happen in other breeds, but I don't want to set myself up for that heartache. I'm also just not that into... dopey dogs. Like, labs and setters are extremely biddable, but are often just super exuberant and not always great with the critical thinking and problem solving. They're lovely and sweet and I find them exhausting and am happy to love on them if they get to go home with their owners afterwards, haha.