This is one of the quickest and easiest dailies to complete for your Argent Tournament prestige. The questgiver asks simply that you kill 10 Scourge units in Icecrown.
Remember, in 3.1 any mob that will grant you quest credit will show as much on their tooltip when you mouseover them. Use this to your advantage and don't waste your time with an AOE pack that won't give you credit!
Given its close proximity to the Tournament grounds, many players are likely to flock to Sindragosa's Fall to kill the Scourge mobs there, including Frostbrood Whelps and Cultist Corrupters. You have some other choices, though -- the Valley of Lost Hope is chock-full of mobs that grant quest credit, as is Aldur'thar, and both are close enough to the Grounds that you don't need to fly all around the zone just to get your quest done.
Crack some Scourge skulls and grab your reward!
Reward: 1 Valiant's Seal and 13g 23s
Editor's note from Alex Ziebart: I happen to like doing the Shadow Vault dailies side-by-side with this one. The vrykul for Leave Our Mark count as Scourge for this quest!