It's just such a loaded question. It all depends on how the recording was recorded, mixed and mastered for the particular format, and then the quality of equipment on which you're listening to it. The best mastered CD in the world will sound like crap compared to an off-the-shelf LP if you're listening to the LP on a $100,000 system and the CD on a Discman and cheap earbuds. Conversely, an expertly mastered LP will sound awful compared to a standard CD if you play the vinyl on a Mickey Mouse turntable. Taking it a step further, many of the early CDs weren't remastered for digital and thus sounded horrible (Fleetwood Mac's Rumours immediately comes to mind), and many DDD recordings of the '90s and '00s that were released in small quantities on vinyl weren't remastered for analog and sound awful.
For me, personally, I prefer older recordings on vinyl and newer recordings based on the recording/mixing process. I'll usually stay away from vinyl reissues unless I know they're AAA or that they're been remasted/remixed specifically for analog. But I won't hesitate to buy CD box sets like the recent Beatles reissues, especially when not all of the material is being made available on vinyl. (Full disclosure: I end up buying the single CD, the multiple CD, the single vinyl, the multiple vinyl and the picture vinyl, because I am a masochist.)
For me, personally, I prefer older recordings on vinyl and newer recordings based on the recording/mixing process. I'll usually stay away from vinyl reissues unless I know they're AAA or that they're been remasted/remixed specifically for analog. But I won't hesitate to buy CD box sets like the recent Beatles reissues, especially when not all of the material is being made available on vinyl. (Full disclosure: I end up buying the single CD, the multiple CD, the single vinyl, the multiple vinyl and the picture vinyl, because I am a masochist.)