Are there any specific types of credit cards you guys are in favor of that offer decent kinds of rewards on purchases? I'm mostly interested in a card that offers a cash back incentive, but what I would like to avoid is a shady bank...and also one that doesn't annoy the crap out of me with phone calls and crap I don't want/need. I'd also like to avoid annual fees. Does anyone use or have the Amazon rewards card? Any thoughts regarding it?