I once went on a locking spree prior to Killzone 2's release because there were ~20 Killzone 2 threads floating around at one time on the Sony forum alone.
The only game that has come close to that so far is Final Fantasy XIII.
Other than that, Brawl is the only crazily hyped game I can think of from the past few years, but most of the excitement was contained in the Dojo thread (which actually had to be deleted form the website once it broke 10k posts, because it literally brought the site to a crawl).
One thing that stands out about Killzone 2 was that it had just as many detractors as supporters. For every person going "that video looked amazing!" you had somebody going "lol Guerrilla Games, Killzone sucked and so will Killzone 2". The reason Killzone 2 garnered so much attention was because it was controversial. You had reasonable threads like this turning into battlegrounds because of posts like these. You had fans praising it as the ps3's first true system seller and others predicting it'd fall flat just like the original.
Of course, this all deals with hype on VGChartz. In the real world, Halo 3, GTAIV, and Modern Warfare 2 are the only games the general public truly seemed excited for.
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