Nigerian Dwarfs are awesome! I have a small herd of them that I breed, milk, raise, and sell! Love the breed!!
What are your plans for goats? If just pets, I would recommend two males that have been castrated. Wethers (castrated males) make the best pets because they are not hormonal. Wethers are also pretty cheap. A wether and doe pair would be the next best option if you want only pets. Just know, does will come into heat every 18-21 days and most are VERY loud when in heat.
Each individual goats has their own personality. Some love attention while others simply don't want anything to do with people.
Wethers are going to to have the most consistent personality as the change in season won't affect their mood/behavior like does and bucks.
Nigerian Dwarf does will come into heat every few weeks for a few days. Most seem to be very vocal when in heat so they wouldn't be a good choice if you have close neighbors and only want pets. However, some does aren't as vocal (or vocal at all) and won't show signs of being in heat unless a buck is around.
Bucks (intact males) are just nasty. They do NOT make good pets at all. They pee on their face and usually have a very pushy, "I'm in charge" behavior. Some will actually get mean and aggressive when in rut (breeding season).
Another thing you'll want to consider is if you want a horned goat or not. I personally do not like horns. They are dangerous, imho. Even if a goat is just playing, it could still accidently hurt someone as goats have very sharp and pointy horns. If you are looking for pets, I would make sure the goats you get are disbudded, especially if you have kids. But really, it's your choice.
I would recommend joining The Goat Spot. There are a lot more goat owners there. Everyone is also very kind, helpful, and knowledgeable. Even if you don't join, you can learn a ton by just reading through old threads. Owning goats can be a steep learning curve and it's always better to be prepared as goats like to surprise us.