Best state for LLC?
Choice of state for your LLC would depend on several factors, and often it makes more sense to register the LLC in the state where you live and not anywhere else. I invite you to read my article about choosing the state of registration (I presented several scenarios and you might associate one of them with your particular business): Choosing Where To Incorporate.
There are a few states that present special interest in terms of incorporation/LLC formation. You mentioned Delaware and Nevada, the third one would be Wyoming. You are welcome to review a comparison between those states: DE vs. NV vs. WY (keep in mind Nevada is the most expensive of the three with Delaware coming second, however Delaware has a few advantages other states don't, but its outside the scope of this answer).