I did not get a chance to play GOD 1 & 2 until the remastered HD version that is release recently. I finished all the 3 installments now and enjoyed all of them. My personal favourite is God of war 1 because the story narration is superb if you watch all the cut scenes as a movie (search for god of war 1 cut scenes in youtube). You would see how beautifully the story is told about the transition from spartan -> ghost of sparta -> god of war.
Some good comments here. I'd have to agree with Orko that the first was my favourite. Perhaps it was just that incredible first boss battle against the Hydra to plunge you headlong in the game, but I enjoyed that one the most. I agree that the epic scale of God of War III was truly something to behold, but despite the old adage that if something isn't broken, don't try to fix it, the formula did seem a little repetitive, perhaps?
Story - God Of War 1 - it stands up as a single standalone story - with a quality narrative, and satisfying conclusion. Graphics - God Of War 3 - built for next gen, this is the obvious winner. Action / Gameplay - God Of War 2
Story - God Of War 1 - it stands up as a single standalone story - with a quality narrative, and satisfying conclusion. Graphics - God Of War 3 - built for next gen, this is the obvious winner. Action / Gameplay - God Of War 2 & 3 - all three were similar, but 2 added tweaks such as grappling, the ability to quick climb ladders, and also removed the awkward repeat press R2 button for opening doors from 1. 3 added greater variety of weapons and more enemies on screen. Sound - all equal - all epic soundtracks, which could easily stand side by side with films such as 300 / Gladiator. Special mention - God Of War 2 - after playing and completing God Of War 1, this was the most eagerly anticipated game release ever for me - completed in a weekend, the first few hours are some of the best gaming I've experienced, and the cliff hanger ending was totally awesome. It also has the longest campaign of the 3 games released, with the most boss battles, and perfect pacing - so is my pick as the overall best.
I like them all, but GoWII is my favourite because I think it has the best variety of environments, an excellent selection of boss battles, some clever puzzles and it added some good elements over GoWI like the swing, counter-attack and time-freeze. GoWI holds a soft spot with me simply because it's the first in the series and did things I never thought games could do (the scale and vistas hadn't seemed possible in a mere PS2 game before GoW), and although I like #3 I felt it was the weakest instalment with a slightly confused plot (I still don't really understand Athena's place in the story?) and kind of just more of the same without any significant additions. However, all three are excellent and I think it was just a case of being a little burnt out by the time GoWIII rolled around.
Despite this though, I still plan on getting the Collection Vol. 2, as I've not played the PSP games and am informed Ghost of Sparta in particular was excellent.