Delaware means suspicious. Myth or reality?
The IRS treats everyone seriously, regardless of what state they are registered in. I haven't heard of any horror stories involving companies registered in those specific states, although rumor says Nevada has some friction with the IRS because they don't like to cooperate with them or something of that kind, but, you know, rumors say lots of stuff.
Besides, at least Delaware is known as the capital of incorporations, and most big companies that are traded publicly (and those small that aspire to) choose that state as the state of incorporation.