Pretty much the only reason you've ever heard of him is because Stephen Ambrose chose him and his unit as the topic for one of his books. If that hadn't happened, he would only be remembered by the people he served with, his family, and perhaps a very small number of military officers who would have regarded him as an extremely minor footnote in the Normandy Invasion.
It's a bit bizarre, but Ambrose, who was legitimately an excellent writer and a sound historian, will nonetheless be best remembered for his most irresponsible and shoddily researched work Band of Brothers (in turn largely remembered because of the successful and popular HBO miniseries that used it as source material). It's a book that has almost as much in common with fanfiction as it does with history. It's unabashedly biased and relies almost entirely upon what amounts to war stories for its sources. Due to the popularity of the book and even more so the miniseries, a practical cult of personality has sprung up around Winters and the other members of Easy Company.
In the book Winters' personal opinions on a number of topics are presented as fact. He insults a variety of people and Ambrose makes absolutely no effort to find alternative sources to either verify or debunk Winters' claims about those people. So as not to be guilty of the same crime as Ambrose, I will admit that I don't currently have access to my copy of the book, and so am working from memory. However I am completely able and willing to verify the claims I make as soon as I return home for anyone that doubts my statements. Examples of the mud that Winters slings include:
-Completely trashing the previous CO of Easy Company, Herbert Sobel, up to and including accounts of what can only be described as mutiny (although it is made clear that while Winters commiserated with the motivations of the soldiers involved, he did not openly encourage it, and in fact took efforts to stop it). Additionally in Winters' defense, he does credit Sobel with ensuring discipline in the unit, which in turn served them well in combat. However that is the entirety of praise that Winters gives to Sobel, and everything else is negative.
-Winters makes several statements throughout the book that either state or imply that Easy Company was head and shoulders above other Companies in the 506th. While it's good that Winters took pride in his unit, it didn't have to be done by denigrating other units that Easy Company served with. It becomes even more questionable when you realize that all historical inquiries into Easy Company's record show that it was pretty much an average unit in the 506th, and certainly not the exceptional outfit Winters would have you believe.
-Winters charges the pilots of the C-47's that were used in the Normandy Invasion with both cowardice and incompetence. Ambrose makes absolutely no effort to investigate their performance, and in fact further research shows there were a great many valid reasons for difficulties the pilots encountered.
-At one point in the book Winters openly admits that he has no interest in being unbiased in his story-telling. The exact details elude me, however there is absolutely one part in the book where Winters is saying something negative about one of his superiors (I believe it was Colonel Sink, although it might have been someone else). Ambrose is a bit taken aback by the venom Winters has towards this officer, and specifically asks Winters if he is being unfair/unbalanced/unbiased. Winters spits back something along the lines of "I'm not interested in being balanced". Out of all the charges, this is easily the most heinous and the most telling, since it directly demonstrates that Winters had some axes to grind, and was not shy about doing so. This should have been a MAJOR red flag to Ambrose, and it's mind-boggling that Ambrose doesn't address it in any shape or form. A major failing on Ambrose's part as a historian.
-Winters was recalled to service during the Korean War and his record during this time is hardly distinguished. During the time that he was called up, he traveled to Washington D.C. in an attempt to convince the Army not to send him to Korea. When they declined his request, he seems to have become disillusioned and did not seem to be particularly enthusiastic about his job of training officers, citing their lack of discipline and poor attendance as the reason for his lack of enthusiasm. He was finally discharged under a loophole that allowed officers that had served in World War II to take a discharge instead of deploying to Korea. It's not hard to understand and believe that Winters was sick of military service by the end of World War II, and indeed had earned the right to a bit of pacifism after all that he had survived. However it is a bit unsettling to think that he was perhaps a bit lackadaisical in his duties, particularly since he had first hand knowledge of the rigors that the soldiers he was training would have to be prepared for. It's one thing to be reckless with your own personal preparation for risk, but something entirely different when your lack of enthusiasm could easily cause others to be ill-prepared. It's even more unsettling when he doesn't take responsibility for his actions, but rather blames his trainees for his lack of enthusiasm. Blaming others starts to seem like a pattern with Winters.
-There's a few other inaccuracies and inconsistencies throughout the book, and a few more lost in the translation from book to miniseries. For example one scene in the miniseries has a soldier who is returning from being wounded in the Normandy Campaign being shunned upon his return to the unit (presumably due to perceived malingering/cowardice which resulted in his missing out on Market Garden and Bastogne). However this was a complete fabrication of the miniseries, and in fact in the book the soldier is greeted with camaraderie and is brought up to speed without any rancor, and it is never even suggested that others thought the soldier guilty of anything. Another error that I recall in the miniseries was the claim that a soldier had died shortly after the war, when in fact the person lived for several decades after his supposed death. Certainly not huge errors, however enough to remind trained historians that they are watching a tv show, not a documentary.
So all this brings us back to your original question. How exceptional and/or remarkable Winters was is an extremely subjective question. However despite all my focus upon his negative traits, it would be absurd to claim that Winters was without merit. Indeed he was obviously a very good leader. His men clearly admired and respected him, and that's usually the only benchmark a good leader cares about. From an official standpoint, he was awarded a Distinguished Service Cross for his actions in the Normandy Campaign, a decoration that is only one rank below the Medal of Honor (which he was nominated for, and might still be awarded if interest groups get their way). He was also awarded two Bronze Stars. Two Bronze Stars and especially a Distinguished Service Cross are NOT the sort of decorations one gets for merely showing up. Furthermore, he was also awarded a Purple Heart, which is earned by being wounded in action by the enemy. While some people have pooh-poohed this medal in the past, or the circumstances under which it has been rewarded (a fairly recent example would be the scorn that some people laid upon John Kerry due to their belief that his wounds were so tiny as to barely warrant the award). There have also been cases where people received the medal due to self-injury brought about by negligence, or other questionable circumstances. However I'd retort that ANYONE that has ever received the Purple Heart was at the very least serving in circumstances that are more dangerous than average. Simply being present in a war zone puts you at greater risk than the average person. There is not a doubt in my mind that Winters' life was on the line, and probably with some regularity. That alone is admirable. While the wound he received for the medal was superficial at worst, it would be disgusting to claim that he did not rightfully earn it.
In conclusion, I would say that Winters was an above average officer who did his best and served with admirable courage and skill. He was also a human being, with all the faults and warts that that entails. He was certainly not a flawless saint, as some believe him to be. However he did all that his country asked of him, and then some. If fault needs to be assigned, it should be to Stephen Ambrose, who should have known better than to paint him as a perfect hero, as well as to those cult of personality types who would rather obsess over insignificant details ("What shade of brown was Major Winters' excrement during Operation Market Garden?"), rather than attempting to understand the bigger picture, or heaven forbid, study any of the other 16 million Americans that served during World War II, about 99.5% of whom did NOT serve in the Airborne, but who have stories that are potentially just as interesting and important.
Thank you. I really appreciate your detailed and thoughtful response. As a documentary filmmaker I deal regularly with similar issues arising from using an individual's story to represent that of a wider group. It requires great care.
Here's a previous thread on him
http://www.reddit.com/r/AskHistorians/comments/16pcws/major_dick_winters_certainly_a_war_hero_but_i/