Manufacturers

Most (all?) of these offer free samples.

Molex is the name of a company, not the big power connectors for disk drives,

All sorts of surface-mount adapter boards. Really useful.

Lots of analog and RF chips. Also many DSPs, including the Blackfin. You can get a Blackfin development board that runs Linux from Digi-Key.

They make the PIC family of microcontrollers. They are also one of the few manufacturers of small CAN bus interface chips.

Among other things, they make some easy-to-use switching regulators.

Lots of DSPs. Also analog, RF, and simple logic.