Absolutely The Scourge. I can connect with The Scourge. Not as if I were the walking dead mind you (ok, some mornings). I mean that I can realize them, their purpose, the threat they possess. From years of playing Dungeons & Dragons (now Pathfinder, much better btw) I’m pretty familiar with the undead and how they tick. When it comes to demons, you tend to have to level a fair bit higher to really encounter the good ones. We didn’t do that very often.
World of Warcraft’s approach is not all that different. Particularly old WoW wasn’t. Undead in the Deadmines, Duskwood, and the Plaguelands to name a few places (and excluding the Forsaken from the discussion). By the time you hit 60, you had more than your share of prominent walking dead. Heck, you also had Naxx back then to stoke the fire. Burning Legion? What’s that? Then came Outland and it still never felt like The Burning Legion so much as it just felt like Outland and there happened to be demons there. When Wrath hit, though, it was full on Scourge Invasion and it felt like it. Most of the expansion felt like you were crawling through the wretched Scourge to get to Arthas in the end. As I say, I feel The Scourge. Can’t say that about the Legion in the slightest.