I had a friend I worked with in High School that was the ultimate one-upper. All the same stories; my uncle designed the B2, my 3rd cousin is Barry Bonds, I can run a 2 minute mile...
Some of his greatest lies were those relating to the HS partying scene. He was always talking about throwing these wild parties... but no one could ever find anyone from our school who attended them. He'd come back with something like "it was spur of the moment and mostly college people..."
Anyways; one time he bragged about being able to down a 1.75 of Vodka in a single sitting. So me, a buddy of mine, and this guy all get together and stay over my buddy's house while his parents were gone. We bought 3 1.75s of Smirnoff and went to town. This guy, the one-upper, just started drinking it straight over ice in 12-14 oz glasses. My other friend and I did the same, but we replaced probably 75% of our vodka with water. The dude damn near did it; he became incoherent with maybe 1/4 of the bottle left. He ended up passed out in the bathtub with loss of all bodily function control. We really got scared he wasn't going to make it, but eventually the sun came up and all were alive to tell the tale.