GoW was a year 1 title for the 360 by about 10 days btw, makes your Ratchet comparison spot on though. Having not played Ratchet I can't say what was the better accomplishment for their system, it or Gears.
Defiantly, I will own a PS3 when FFXIII comes out, but until then I can't justify the cost.
They are all great platforms in their own ways.
Don't take my comments the wrong way, I am just saying the 360 and PS3 are almost Identical in performance/potential.
Where the PS3's Core is superior to the 360, the 360 has a superior graphics card/branch prediction. Equalizes the equation IMHO.
PS3 has more storage, but blue lasers (both formats) are really slow compared to DVD speeds. (in future generations this will change)
Yin/Yang
Still don't believe a Sony Movie format will ever survive (betamax, umd, etc) but they can prove me wrong.