you can try one of those bigger online places, like ebizfiling or one of their competitors that advertise on adsense when you enter ebizfiling into google.
ebizfiling has been running TV ads. You would have to think that would be a good sign of legitimacy, at least.
Sometimes going with a smaller company is much better. Make sure to use only companies that have good feedback from existing customers. Always double check what resident agent are they using and what are the fees for next year. Many people get slammed with $250+ recurring fees per year when a better residential agent will cost you <$100.
If you are a do-it-yourselfer, just go to the Nevada SOS website. All the forms and information are right there. Search for "Nevada SoS" and you'll see the site.
I started my first company with corporation.com registering a s-class corporation out of carson city nevada. Then when we had enough we properly incorporated out of nebraska. (my home state)