Quite a vague question that's likely to generate highly subjective answers. Anyway, for average Nepali students, I reckon Minnesota (Mankato in particular), Oklahoma and Texas are the 'best' states. Tuitions are comparitively affordable and the quality of education is quite good. Essentially, you can fund your own education - a driving motive for a horde of Nepalese to the US. 

If you're a young family that wants to raise kids, I'd say most midwestern states are most ideal - Lower crime rates and significantly 'cheaper' living conditions. Madison, Denver, Dallas, St. Paul-Minneapolis are some cities that I can think of right off the top of my head. 

If you're young professionals wishing to explore and enjoy good vibes, cities like San Francisco, Seattle, Chicago, Portland, San Diego, NYC, Boston are incredible. 

If you're already set with a decent job/career, I wouldn't wanna live anywhere except for San Francisco Bay Area and/or LA/San Diego. Perfect Weather. Diverse. Opportunities. Great place to live overall. The entire state is a gold mine. But again, it is a subjective opinion. 

However, all things considered, I'd say North Carolina (Durham-Raleigh, Cary) is probably "best" state. It is an amazing state with a ton of educated people with quite a booming economy. What makes it even more attractive is the weather (unlike most states in midwest w/ extreme weather) and a significantly 'affordable' living condition (compared to states like CA, NY or MA). 

Since you're in the US, you should be fine as long as you avoided shady neighborhoods and states like MS, AK, WV, AL, WY and MT (WY and MT are beautiful, though).