I'm an attorney. Delaware is definitely not the cheapest or even in contention for the cheapest. Still, if you want to raise capital, the correct answer is DE C Corp. If you're not looking for external funding, any state will do. If you care about anonymity, do Nevada or Wyoming. If you don't care about anonymity, Colorado is actually a very good choice. Very simple, intuitive online filing system that accepts filing…
Would Nevada/Wyoming be a good deal if they lived in the US? Let's say, living in Texas.
Unlike Wyoming and Nevada, Texas does have franchise tax, but that is 0 until you exceed $1.23M in revenue, and it maxes out at .331% or .75% after that (https://comptroller.texas.gov/taxes/franchise/).
Delaware has all of these (personal, which wouldn't apply if you live elsewhere, corporate income tax, corporate franchise tax, minimum $400 annually). Wyoming costs only $50 to incorporate but has a $50 annual filing fee.
Also, you'll probably need to file foreign corporate status if you have employees in Texas but are incorporated elsewhere, which is about $700 (one-time).