QUAKE LIVE
Above is when an FPS needs actual skill. Nobody to blame but yourself if you suck shit at it. It isn't that popular, because mostly everybody sucks at it. In COD you can mask your shitty skills with your high level cap, pretty banners and cheap weapons, not in Quake baby.
There is such a big gap between a beginner and a middle range player in Quake. Whereas in COD or any other modern FPS, the gap is low to pretty much nil. Noobs in COD can trade kills with players who have been playing much longer very evenly. In Quake, a noob can't even get a lucky kill out of 100 against a more experienced player.
No blaming the guns, maps etc. sucks that these type of FPS are dead. Last one that required skill was CS.
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Fun fact, COD4 IW Engine is a modified Quake 3 engine. Which means that there are most probably lines of code from Quake 3 (1999) in COD Modern Warfare 3 (2011)
So basically, they just kept building and building feature after feature to the Q3 engine since 1999.
Anyway, kind of off topic from my rant, I reckon they should make leveling in COD actually SIGNIFICANT. Like in Starcraft 2 where only the baddest motherfuckers can get into Grandmasters League. I propose that the top 1% of COD players should be able to rock gold guns and prestige the 15th time or whatever it is now, instead of the dickhead who spent the longest time playing.