Blu-ray with occassional streaming
... or vice versa. I occassionaly purchase movies on Blu-ray disc because: 1) The picture quality is better; 2) The HD surround sound is better; 3) Only for movies I deem as "must-have"; 4) To replace existing DVD, VHS Tape, or laser discs deemed as "must have." I also rent Blu-ray discs and only use the streaming services as a convience for movies that are not on my A (purchase) or B (watch) list. Like you, my buying is down to a few titles a year. Purchasing titles will stop when streaming movies are available with the same visual and audio quality of Blu-ray or better (4K picture quality is in the pipeline), the price of Internet connectivity comes down, or the discs become cost prohibitive to purchase.
I have a decent home theater system. The picture and sound quality of Blu-ray far outpaces anything that I am able to watch via streaming media (of course some of the "quality" difference is because I don't have higher speed Internet service which is cost-prohibitive for me).