I have spent a good portion of my career working at law firms doing research that won new clients and lawsuits. The nature of this research was quite wide in scope--'all over the map' on legal, technical and business matters.
During those years my favorite, trusted sources were the leading fee based vendors, Westlaw, Lexis/Nexis, DIALOG, D & Bradstreet, Hoover's, etc. because they brought value add to their products and had user interfaces that enabled a focused, effective search to be run.
I have also done a good deal of primary research which has also been fruitful and sometimes amazing.
Of course, today with the Internet, there are SO many more avenues to go down....
Speaking solely about Competitive Intelligence, can someone share with me their favorite resources for B to B CI research -- those requiring a subscription or not.