After a few small projects with the Arduino you may realize that the program memory for the sketches is rather small sized. So it is time to search for something bigger. You should look at the Arduino Mega 2560, which almost brings much more program memory, tons of new ports, more variable memory and additional static EEPROM memory with it. It is worth noting that the board has 4 hardware serial ports, which makes communication between other Arduinos much easier.

Arduino Mega 2560 (in this case, a cheap Chinese clone)

Specifications:

• Atmel© ATmega2560 processor with 256KB Flash (of which 8 KB are used by bootloader)
  8KB SRAM, 4KB EEPROM, clocked at 16MHz
• 16 analog inputs
• 54 digital inputs or outputs (15 with PWM support)
• USB port
• I2C support
• 4 serial ports (UART)
• 6 interrupt ports
• SPI interface
• 1 LED an Pin 13 for own use
• Power supply 7-12V DC
• programmable with the Arduino™ software

Example circuits and projects with Arduinos:

Mood lamp with a digital RGB LED Strip (WS2811), an Arduino, acrylic glass and a few parts from the hardware store
Simple indoor climate monitoring with an Arduino, BMP085, DHT11 and a RTC
A 1.8 inch TFT color display (HY-1.8 SPI) and an Arduino

Components:

eBay:	Arduino Mega 2560
Amazon:	Arduino Mega 2560

Good?