One of the reasons for the steap decline of FPS games is the absolutely pathetic amount of RAM featured in Xbox 360 and PS3. Good luck producing some quality level design when making something that has to run on those toasters.
Even if Gears Of War spawned the term "popamole", I'm struggling to think of any other games that felt just like GOW.
To be honest, every single war fps that came out kind of blurs together in my mind, with the exception of the Arma series.
Edit:
By which I mean that, if you were talking about gears of duty and suddenly switched to call of war, I wouldn't even notice.
Even if Gears Of War spawned the term "popamole", I'm struggling to think of any other games that felt just like GOW.