Well, I think I have to make a better analysis to explain my point a bit more... xD
I like Blizzard a lot, they make very good games and, like Mechanical Man said, very moddable.
Relic, on the other side, is a smaller company, but makes high quality games too; its philosophy is also different: Blizzard tries to make 3 brands more perfect with the passing of the time (Warcraft, Diablo and Starcraft), but they are always the same thing; Relic is trying to make different games with a wider selection of titles but they are often imbalanced due to the innovations they always make.
At this point, it's a very hard choosing for me, so it's time to view it from my personal point of view: I prefer Relic's a lot more in this case. Sure, Blizzard's Warcraft III's WE is a great thing, but I've never been impressed a lot by the skirmishes (and Starcraft's too); on the other hand, I always liked a lot Relic's games and I prefer a lot more their features, factions (WH40k of course) and such.
Anyway, it looks like that Relic won in that competition: 3026 votes against 3012... a very small difference, afterall. =)