In reply to henbot: Not sure about steepness, but as far as I'm aware Nanga Parbat's Rupal Face is the biggest single face/ slope on earth, well over 4000m from valley to summit. Annapurna's South Face comes pretty close with around a 4000m (8091m- 4400-4000m) drop, and it's pretty steep too.
Talking of Chomolungma's Kangshung Face, does anyone know if Lhotse's NE Face opposite it has been climbed?