Blu-ray. I've got a 1080p 3D TV and they look fantastic. The movie doesn't have to be in 3D (that's mostly there for games), but I still appreciate it as the most artifact-free and colorful experience. I've compared DVDs and BDs, and besides the resolution, the color depth is a great advantage. I also like that the discs are nearly scratch proof. I take good care of my stuff, but I still notice scuffs on DVDs, it seems inevitable and it's disappointing to see. There are many BDs out for around $10 nowadays, so there's a wide selection of relatively inexpensive material available and it's nice to get it on BD if possible. I have a media server to which I rip my DVDs and CDs, and I use it a lot, but if there's something I really like, I'll get it on blu-ray for sure.