The ultimate and only correct response to the phrase "cool story bro". If you use this against someone correctly, they'll shit entire houses, much less bricks.
You: I went to the mall the other day and bought the most shitastic pair of vans.
'Friend': Cool story, bro.
You: Pro reply, sis.
'Friend': Haha, that's funn--holy shit... I feel something coming...
You: Yeah, I know you do.