To be honest, I liked a lot of Stephen Ambrose's book as an update to Cornelius Ryan, but he's taking the "it was the guys who fought on Omaha that turned the tide of the war" bit somewhat too far. By 1944 the war had turned already (Stalingrad and El Alamein were the turning points). That and Ambrose's almost exclusive focus on the US landings didn't do credit to the actions by the Brits and Canadians who were also landing on three beaches as well. While I would agree that the battle at Omaha was the most significant part of that action, I think Cornelius Ryan's approach (if dated) was a bit more balanced.
THat said, I did like Ambrose's Band of Brothers, but can't decide which I liked better- the book or the HBO series (which even my wife -who hates war flicks- loved).
Alright, and why I like Thin Red Line- it's a different kind of war movie. So many war films are essentially the same layout. The theme of valor is perhaps the most over used theme in any war film. Look at the Sands of Iwo Jima- here you got valor, you have a landing on a hot beach (Tarawa) and you have sacrifice. Look at Bataan- again you have sacrifice.
The Thin Red Line got you into the minds of the people fighting, what they were thinking and the issues had have- from the colonel who is trying to look decisive and sends his men on a foolhardy attack, to the guy who just shot someone and is trying to morally deal with that. One of the best parts is where a lieutenant tells his scouts to go ahead. THe Scouts look at him like "what are you fucking kidding" he sends them ahead, and they both get popped in a blink. Yes, there were some long parts and sometimes it got a bit boring, but war is sometimes a bit boring, but the action scenes were pretty intense and realistic. But the best thing about the film is that it examined the idea of war not as an anti-war or pro-war flick, but as a condition of human nature, and as such a natural condition. I don't think any film has done a better job of that, or raising new issues. Yes, a Thin Red Line is a more difficult film because its new- much like Catch-22 was a difficult film. But I think it was a better film than something we have seen before in a new package.