What products, deals or other incentives are available exclusively to those paying with Bitcoin? Occasionally I'll see an offer that is available only to those who pay with Bitcoin.

What products are sold in which no other payment method is offered, or other offer extended only to those paying with bitcoins?
The only payment method for Bundles through Nestor Games is in bitcoins.
Items in BitPremier's showroom are available only when paying with bitcoins.  Since some of these items are not otherwise available this might indicate Bitcoin exclusivity.   
Author James Altucher made Bitcoin as the only payment method for his new e-book (for a limited period of time)