Al Mansoor Video is probably the largest and most trusted name in Indian movies, DVDs, music, etc. They have a great collection of Indian music in all languages from the golden years to the latest tracks that are out. They also have DVDs from yesteryear and today that are excellent. I have purchased DVDs from others who claimed that they were originals and not knock-offs. But it turned out they were horrible prints.
These carry top shelf items and guarantee that the DVDs and CDs are originals and not some cheap rip-offs. The prices are actually very good. They don't really have sales, but they give good rates and are ready to give you a discount if you buy a decent amount.
I used to go there a lot when I was studying at Northwestern and stock up on the weekends. I still stop by if there is a movie I really want to see.