I wouldn't move to Texas. I view Texas as being ultra conservative and I don't want any more to do with that then I have to. It's bad enough in Missouri with these right-wing nut jobs. Texas is arid, dry, and hot. Yuck! Who wants that? I guess your oil people are going there and sure there's money from that, but that's not exactly a infinite resource.
I don't think you can just pick one state and call it the best. It may be the best for some people, but I don't think it would be the best for everyone. It really just depends on your lifestyle and your preference. Good for those people though, moving where it makes them happy.
No I do not think that Texas is one of the best places to live in the United States. Considering there weather it is an extremely hot state and many people cannot take such high temperatures. I prefer places on the east coast as the best places to live particularly states that experience all four seasons.
The argument that every one's moving to Texas is a contentious issue as it would suggest that the rest of the USA isn't worth moving to. Whilst Texas has a good standard of living it also has a troubled human rights history and gun laws for one make it more dangerous place than more liberal states.