I was forwarded this PDF from a colleague a couple of weeks ago. It contains 20 great B2C, B2B and nonprofit email designs. The collection was currated by Responsys, the email delivery company.
Here's the official summary
Every year, the global Responsys team pulls together a collection of their 20 favorite emails, ones that are at the leading edge of design, messaging, coding and strategy and come from the brands that are pushing our industry to be more innovative, curious and creative.
Our fourth annual compilation has B2C, B2B and nonprofit brands adapting to the mobile inbox environment, using animation in new and interesting ways, and embracing the newest social media star, Pinterest. Each piece on its own stands out as a great example of email creative, but when viewed together, this collection illuminates the priorities that are critical for our industry: Evolving Inbox, Something Unexpected, Personalized Content, Automated Programs, Defensive Design.