I have a ps3 and a 360 and can tell you the ps3 is a better console, the online isn't as good but it keeps getting updated and its free.
assassins creed is good but repetitive.
you said you like the god of war games so you'd have that coming out end of this year/early next year.
Devil may cry 4 is great and it lasts you a long time.
And as for medal of honour, stuff that and get Call of duty 4.
Theres also games like haze and metal gear solid coming out which are exclusive to the ps3