It's gotten to the point for me where I can only play NES, SNES, Genesis on a CRT, and I have my Dreamcast and newer systems hooked up to my HDTV. I have never gotten used to seeing 8/16 bit graphics on a flat screen TV meant for newer media. The Sanyo CRT I have is from 1992. The picture does some goofy stuff with random lines showing up and the brightness jacks up randomly but it's not to the point where it makes gaming unplayable.
The only reason I would ever ditch the CRT is because it takes up more room.