I dont often watch DVD's on my computer, but when I do, PowerDVD does the job wonderfully
I've never really bothered to try anything else, as using the hardware player in the lounge is much easier (and has a bigger screen/tv )
I like PowerDVD the best, but sometimes WMP works fine. Once you install any DVD decoder, you can use WMP to watch DVDs (providing you have a DVD player of course ). You can also download a DVD codec seperately so you don't need any other software besides WMP if all you want is a simple interface.
PowerDVD all the way, I've been using it for a few years. No problems yet. It seems, if you're fine with the program you have been using, you won't change to another, even if it is proclaimed as better.
I use NvDVD it has good a/v play back and it plays .vob files which means u don't technically have to have a DVD rom in the pc with NvDVD on it, u just have to have enough room to hold the .vob files on your hard drive.
its good if u like to watch one particular movie alot ie; shrek and u also like to play a game alot that takes a cd to start and u don't like to swap and I only have room for one drive and I rather it be a CD burner then a DVD rom