Gevalia! Beats every other brand, hands down. Peets is also very good.
Gevalia is what I buy (in bean form) for the non-decaf I use. When I grind the beans for our pots of coffee, I use 3 scoops of Gevalia French roast with 6 of the World Market Italian roast Decaf. I like my coffee to be of near espresso strength. I can get regular Gevalia beans @ Kroger; unfortunately, no decaf Gevalia beans.
I also like the Green Mountain Italian Roast Decaf for my Keurig brewer. It's the strongest, most flavorful Keurig decaf I've found.