Quiplip actually has a couple of different series- my favorites are the original Quiplips line and the Graphitudes line.

Most of the Quiplips line of cards have loads of text on the front cover, including several "choose your own" options. For example, one of their birthday cards starts out with this:

In honor of this very special day, I set out to find you the most sublime, extra-fine gift imaginable. I scoured the globe, searched high and low, but ____ all of the precious gems combined couldn't sparkle as bright as you ____ there was not a single flower that came close to the beauty you possess ____ no beer of the month club could satiate your ibncredible drinking capacity ____ no book was worthy of your all-knowing eyes

And so on.

The Graphitudes line features pie charts and bar graphs with witty little sayings.

Good stuff.

Hysterical. The smartest cards I've ever seen.

Quiplip has the smartest, funniest cards ever.
Friend's even call to thank me for giving such a unique card.. (via libellus)