In my experience, Alpines tend to be more assertive than other breeds. Some like that, others find it a challenge. Of course, as said, all goats are different even with in a breed.
Nubians, sweet, needy, loud, less 'bright.' (my least fav, even if they are pretty, lol)
Saanens, calm, mild, even temperment, some can be boring.
Lamanchas, intelegent, calm, sweet. mot boring like saanen, but not into trouble like alpine.(my fav.)
Alpines, intelegent, independant, assertive, can be entertaining.
These are the ones I have most experience with. I have heard good things about Obers and Nigies.
Glad to see that you are doing research before buying the cutest goats.

How many goats are you looking to keep? If you are not going to have many, then breed may be less important than the characteristics of individual animals. ie, if you only have a few, who cares what breed, as long as you like them. And what would your kid market be, as milkers, breeding stock, or dinner. See what is in demand in your area, if you breed to boer buck, then dinner is marketable and you don't have to worry about different bucks. (but find a boy without a huge head if you do this.)
hth