My son has always been known for calling a spade a spade, to the point where we couldn't let him talk to anyone for quite a while - one example of his brutal honesty when out with his grandparents (they let him talk), sitting outside a shopping centre he was approached by a nice lady who asked him his name, he replied with 'hello you fat old lady'...needless to say his grandparents didn't let him speak to anyone again for some time.
My other memory of cute things from my kids is not a quote, but at an action. My son was nearly two at the time (not the one mentioned above), was woken from his nap to be told his father had an accident in the workshop and had cut his thumb off and was going to hospital in an ambulance - he came out to the ambulance (his father passed out on the ground with us all crowded around him) and tried to administer a Band Aid (sticking plaster) that he'd found in our bathroom. No, he didn't go on to work in a medical field - he's now a carpenter!