If the stickers are hard to tell, the first thing I look at is the etched font. "GAMEBOY ADVANCE" has a very distinct style to it. Most fakes can't quite pull it off. That slightly italicized slant.
Cant see the Pokemon games too well, but Minish Cap is blatant. Looks like generic, typing font, not Nintendo's special logo, also, on the back, look at the quality of the Nintendo name etched into the plastic. Most fakes can't get the oval around "Nintendo" right.
Also, Gameboy is one word. There is a SMALL space between the E and B on offical products, but it you see it distinctly broken into two words, it's fake.