Intervideo WinDVD has issues with my video drivers. I have to use old drivers, because the new ones have that f*cking Macrovision sh*t that won't let me play DVDs because my video card has a TV-out (the logic/reasoning behind this baffles me). I used to use WinDVD because it gave me a better picture than Cyberlink PowerDVD. I have to use PowerDVD (this later version has far better picture than older versions). I prefered WinDVD because it only used 1 Windows tab (at the bottom, like any other window), while PowerDVD uses 2. Also, WinDVD remembers the window size when you maximize/shrink it, unlike PowerDVD. I'm always looking up stuff on imdb.com when I watch a movie on my computer, so this is important to me. OTOH, PowerDVD has screencapture, while WinDVD (older versions, I can't speak for newer ones) didn't. It captures it to a .bmp so you'll need Photoshop or PSP or something to convert them to .jpg or whatever.
BTW. Windows Media Player can run DVDs, but I don't particularily care for the way it does them.
HTH.