A 28 pin 8 bit microcontroller in a DIP package as used on the Sumovore Atmel Brainboard add-on.
The 74HC595 is very useful in expanding how many pins a microcontroller can write to. Use 3 to write to 8!
The 24LC16B is a16K Bits x 8 I2C serial EEPROM device.
Handy for extending the "brain space" of any microcontroller!