I will give you the full list of the Metal Gear games in chronological order, top to bottom: Metal Gear Solid 3: Snake Eater Metal Gear Solid: Portable Ops Metal Gear Solid: Peace Walker Metal Gear Solid: Ground Zeroes (Not yet released) Metal Gear Metal Gear 2: Solid Snake Metal Gear Solid/The Twin Snakes Metal Gear Solid 2: Sons of Liberty Metal Gear Solid 4: Guns of the Patriots Metal Gear Rising: Revengeance All of these except Portable Ops can be played on PS3, but luckily, you mentioned having a PSP. Metal Gear and Metal Gear 2: Solid Snake are older, 8-bit games from the late 1980's, but they still hold up even today, especially the latter. You know that Metal Gear Solid is on PSN as a PS classic, but there's also a GameCube remake called The Twin Snakes.
It's more faithful to the story as established by the rest of the series, and quite frankly, it's just better. You didn't mention having a GameCube/Wii, though, so the original will suffice. The Metal Gear Solid HD Collection, for PS3, contains Metal Gear Solid 2, 3, Peace Walker, Metal Gear and Metal Gear 2.
Revegeance comes out in a little under two weeks for PS3, so there's something to look forward to! If you want to absorb the full story, I'd highly recommend playing in storyline order, the way I posted above.
2, 3 and PW came out as a HD collection on PS3. You should be able to get all 3 at once (search 'HD C' on the PSN store and it should appear on the right hand side). As for the order... Well, I played them as they came out (except PO) and i'm still baffled by the story - enjoyed them though.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.