@tiberboi The 2 GB is more than good enough. Like I said - you'll never use more than one.
Take the extra money and spend it on a fan, heat sinks, a strong power supply and a case. You'll get your moneys worth.
but if your heart is set on N64, PS2, PSP or Nintendo DS/3DS titles; the ODroid can handle that much better; while still running RetroPie through Ubuntu or via The Retro Arena distros.
Which Odroid model do you refer to here? (or maybe a better question: which odroid model handels these kind of games best?)