I think the answer will depend on what type of work you plan on doing and what your budget is. If you have the funds, I’d recommend starting off with a basic set of Lie Nielsen bench chisels:
http://www.lie-nielsen.com/catalog.php?sku=bescset
You can get a basic set of five chisels for $275. Of course that price is a bit steep for most people. For those with less money to spend on chisels, I’d recommend a basic set of Narex chisels which you can get from Lee Valley.
http://www.leevalley.com/en/wood/page.aspx?p=67707&cat=1,41504
I own the Narex chisels myself and find them perfectly adequate for all that I do. An in between suggestion in cost is the newer Stanley Sweetheart chisels—I think Amazon has them for the cheapest.
I’d also recommend getting some mortise chisels—you can get by with only 1/4” and 1/2”. Both Lie Nielsen and Narex make good mortise chisels.
-- "hold fast to that which is good"
