That's a tricky question. Everyone will have their opinion, which is affected by the experience they've had with a particular goat. Nubians are very common for milk goats, reasonably friendly, and would be EASY for you to find in TX. I've got some good contacts if you'd like, both for meat goats and dairy.... in the central texas area (College Station)
Personally, we are torn between Nigerian Dwarfs, and la Manchas. The laManchas are large goats, but all the ones we've interacted with are calm, and nicely quite, which balances out their size. A biggeer goat means a large udder, and fewer total goats to milk each day. But, it seems our large ones have to eat more hay per unit of body size than the small ones. In other words, we think we are spending more money on hay to get the same amount of milk out of the large sized ones.
We really like our Nigerian milkers, but if you started out with a full size goat, its hard to switch to a Nigerian because the teat feels too small in your hand when milking. Better to start small, and move to large if you don't like the Nigerian Dwarfs. Of course, being a smaller goat, the udder on a Nigerian is smaller, and won't produce as much each day, but if you choose the right bloodlines, there are some excellent milkers out there, that give a high % milk compared to body size. We find ours to be efficient feeders. A thing we really like about the Nigerians, is your can push them around. If you need to trim hooves, get a stubborn one up on a milking stand, move a mama and her kids, etc., you can simply push, or even pick up the goat and put it were it needs to go. With the larger ones, if one decides to be stubborn, you've got to spend more time and effort moving it around.
Friends of ours have had bad luck with Toggenburgs being grumpy, but we don't have personal experience.
Boer goats are specifically designed for meat. However, if you are wanting milk too, a good option is to start with the milk goats. To get the milk goat to freshen, you need to breed her, and you're sure to get buck kids. Milk goat bucks don't have as broad muscles as Boer do, but if you keep them as wethers and raise them for 6 months, they still give you a fair amount of meat. Of course the doe kids add to your milking herd, or can be sold to others.
If you do not keep a buck, (or keep him MILES away from the herd) Your goat milk is quite nice tasting. It is not exactly like cows milk, but its a small taste difference. I think its a similar amount of taste variation as between say Whole and 2% cows milk.
Wow, that ended up long. Hope its helpful!