Thanks, everyone, for the responses!
I built the PC around 2006/7-ish (2.4ghz E6600 (dual core thing from the stone age

) & an upper-end mobo, with other comparable components), so compatibility and computing capacity are not problems. I was thinking of buying blu-rays but, as kit brought up, I could just find copies of the rips of most movies. Beyond that, I wanted to use blu-rays for backup purposes (no desire to have suitcases of floppies

). (In fact, the way the pc will be set up, the only purpose of the blu-ray burner will be for making backups, so... heh.) And like the rest of you said, I could just obtain either of those software solutions for bluray playback if I ever need to deal with hdcp.
Alrighty, I guess there won't be problems with just buying the drive, a few discs as needed, and getting that software. How do your software packages compare with the free codecs I mentioned & their own renderers? (Is that just a matter of adjusting some setting in one thing or other? I notice everything playing through VLC is dullish compared with cccp's player.)