If Germany had indeed won the war, it would depend on when during the war they had won. What I mean is this - If Germany was able to stretch it out another five to ten years and somehow exhaust the Allies and win that way - the world would be in ruins. At least the western world would. Remember also that they would either need to survive or prevent a nuclear strike like what happened in Japan, as they suffered the atomic fire for their stubbornness. In this world, there wouldn't be much left to rule over either way.
If Germany had managed a decisive victory, say - exterminating Dunkirk, repelling the Normandy invasion, and following through with their plans to attack U.S. mainland, perfecting the cruise missiles, along with invading Soviet Russia at the appropriate time; Germany would be relatively well off, and the war for them probably would ended around 1944. Also, it would help a great deal if Hitler hadn't made his engineers and scientists chase technological insanity like the Landkreuzer, and other assorted marvels.
So they win, now what? Well, first you have to consider one very important person. And I don't mean Hitler.
Dr. Morell.
No one knows where this obese, foul smelling, disgusting man came from. All anyone can really find out is that he was a quack doctor for German celebrities, and somehow the Fuhrer caught wind of him. After he came Hitler's doctor, Hitler underwent some changes. Firstly, he was extremely energetic, but would go on to become akin to a walking to corpse. Secondly, the man's temperament swung back and forth, much worse than before. Thirdly, Hitler became unhealthily attached the late doctor.
None of the general staff liked, much less trusted Dr. Morell, Eva Braun had complained to Hitler many times about his stench. Hitler's personal doctor (who was doing a fine job) spoke very bluntly about Dr. Morell and was promptly reprimanded and removed from his position.
Over the years, Dr. Morell injected Hitler with impossible doses of amphetamines, fed him strychnine, and various other poisons. This culminated in Hitler during the latter stages of the war unable to walk without aid, as the left side of his body was mostly unresponsive (stroke), and it's been supposed that he had a heart attack. There was a medical journal which Dr. Morell would consult regularly and there was a page torn out, specifically how to diagnose, and treat heart attacks. Given the neuromuscular degeneration one would see from constant, rampant overuse of amphetamines simply to function - Hitler wouldn't have lasted very long at all. I didn't even mention his IBS, but honestly with everything else, I don't think I have to.
Hitler would've likely died from multiple organ failure or some other catastrophic failure. In the time before he died though, MAN! There wouldn't been some crazy advancements every-which-way. Because they wouldn't care for the safety precautions that we have now when we test things, they would've shot ahead with lightening speed. Discoveries in all fields, be it medical, physics, agriculture, they all would've been far more frequent, and it's even possible that they may have discovered time travel.
Personally, I believe Germany won WWII. There are too many inconsistencies and 'conveniences' that came about during the war, namely Dr. Morell. I believe Germany won, they had an incredible technological advancement, but since it's probably would likely have been some kind of totalitarian brutal government - that perhaps prompted Dr. Morell to come back, and change the war.
H