Ah, those pesky PC games (PC here includes Macs), fiercely resisting the ever-renewed dogma announcing the rise of browser-based apps at the expense of the desktop. World of Warcraft, arguably the most successful internet application worldwide (1.5M+ paying subscribers with peak concurrency above 500K players), more or less maxes out CPU utilization on a 2GHz box.
Moreover, it dwarves the money made by about any web app you hear so much buzz about these days. The application has its quirks, the API is poorly documented (though that didn’t prevent the emergence of quite a few add-ons) some servers are hardly playable because of serious lag issues, but the game is addictive. It goes so much against the whole web 2.0/mobile blah blah, the software even comes in a physical box!
Web professionals easily impressed by developers making progress within the severe constraints of the browser should remember what really makes regular people go… WoW.
11/03/05 update: On a scale from zero to five.