Inter IC Communication or I2C is a two wire serial communication bus used to connect a variety of external peripheral with a microcontroller. Most common are EEPROMs, RTC, Port Expanders etc. Most leading MCUs comes with at least one dedicated I2C host adaptor built in.
The OneWire protocol which in fact needs two wires (data and ground) is fantastic for many reasons: you can have a very long cable (250 feets), you can have multiple devices on this cable and with a simple code you can poll those devices to get temperature, voltage, switch position, wind speed, etc.
What can we say about a standard text LCD? Nothing else then for 90% of your project you usually begin with this LCD. With those friendly functions you will be able to begin your projects without loosing time writing code for the LCD.
There is many interesting things about Nokia 3310 LCD: low price, easy to interface via SPI port, can support graphic and text and low current usage.