If you look closely at CFL bulbs, many have a "CRI" rating. A CRI of 100 implies that you're getting the same kind of "full spectrum" that you get from the sun, which is to say that you're getting a nice smooth curve if you plot energy against wavelength. Incadescent/halogen bulbs tend to have high CRIs, while florescent bulbs tend to have lower CRIs. The latter improve their CRIs with funky coatings that absorb light and emit it at different wavelengths.

(One place that this matters, in practice, is that your clothes may look different in your closet than they look when you walk outside. Two things that matched suddenly don't match, since different textiles respond differently to different wavelengths of light. Not an issue for me, but would really piss off my wife.)

The *lowest* CRI you could get, I suppose, would be to use a video projector sending out an all-white signal, since it's really just sending out a light spectrum with three spikes for pure red, green, and blue and nothing in between. Sony makes a funky screen which takes advantage of this, reflecting the specific projector wavelengths and absorbing the rest, thus giving you deeper blacks.