What are properties of a good coffe brand?

I'm in search of a great new (commercially-available) brand of coffee for home-use in making both espresso and drip coffee. I used to frequent a local roaster, but I'm a poor grad student and I have to start finding something less artisanal that fits better in my budget.

I know what coffees I like in terms of taste, but I thought I would ask the foodie experts what some "rules of thumb" or properties are of a good brand of whole bean coffee. (And if you happen to feel strongly about one particular brand I'd love to hear your favorites!)

Along the same lines, does anyone have experience with Trader Joe's coffee? They have the best "bang for your buck" but I've had both good and bad luck with other Trader Joe's products and I was wondering where their coffee fell along the spectrum.