Here are a couple of other rare spawns from the Eastern Plaguelands:
Ranger Lord Hawkspear, Level 60 Rare Spawn, Quel'Lithien Lodge, Eastern Plaguelands. You have to be Horde to kill this guy because he is a High Elf and is, therefore, friendly to alliance players (just like Duggan Wildhammer).
Loot: Killed this guy many times but can't find any of the loot screen shots I took. I'm sure he always dropped greens and no blues though.
Deathspeaker Selendre, level 56 rare spawn, a member of the cult of the damned, so killable by both Horde and Alliance, can frequently be found in the Noxious Glade. Pretty much the only people who go up there these days are people grinding Thorium, so not only will you find this particular rare spawn up there almost 100% of the time but you will usually find a rich thorium vein up there too, grinding thorium in the Eastern Plaguelands is a great way to make money on my server, stacks of Thorium Ore are currently selling for 45g per stack.