The best-kept secret at the apple store is the refurbished mac. You get:
1. Same one-year warranty as new
2. The computer carries the same eligibility for Apple Care as new
3. A computer which has undergone two sets of rigorous quality control testing
4. A savings several times that of any coupon or promo code
Anecdotal evidence on several mac fora indicates a universal pleasure with apples refurb work. Users report receiving computers indistinguishable from new (save for the different packaging refurbs receive), and fewer problems than the users of brand new machines. And this makes sense - refurbs have gone through a second and more rigorous testing procedure.
On a personal note, my Apple purchases have been nothing but refurbs for the last several years. I am happy to report that all purchases (both macs and ipods) have been free from any defects and my wallet has been ecstatic.