Disk for sure. I own something tangible and I'm able to play it years down the road where as digital doesn't give me that sort of security. There's always a risk of destroying the disk but if you actually take care of them it'll be just fine. I also like being able to buy or sell them at a discount and being able to haggle the price. Yes companies can have digital sales but at their own leisure could be months or even a year.
Plus digital is just a boring concept to me, I like collecting and displaying so I avoid it at all cost unless it's on PC... Which I still hate doing but yeah.