The successor of the all time classic that shortly became a hit just like it's "father". The fact that Gameboy Advance plays the older Gameboy titles means you get to use the older games. There is also another version of the Advance called SP.
Specs:
CPU: 16 MHz 32-bit RISC-CPU + 8-bit CISC-CPU
Memory: 32KB WRAM + 96KB VRAM + 256KB WRAM
Screen: Reflective TFT Colour LCD
Screen Size: 40.8 mm x 61.2 mm
Resolution: 240 x 160 pixels
Display Ability: 32 000 colours
Sound: Mono speakers, stereo headphones
Multiplayer Options: Up to four GBAs, up to two GB/GBCs
Power: Two AA batteries, or battery pak
Battery life: 15 hours for batteries, 10 hours for battery pack