Orange Beautiful's paper treats bring a big smile to my face. Not only are their cards gorgeous to look at, but they are impeccably well-crafted and perfect to send to pretty much everyone. Along with their letterpress card line, they do beautiful custom work you should definitely see. Be sure to also check out their etsy.
Along with their oodles of talent, they have a top-notch blog called the Scoop (I hope you already know about) where Emily and Laura showcase their fabulous finds.