CRT effect
Applies a CRT effect, simulating an old cathode-ray tube television.

You can tweak the scanlines (their width and contrast), add screen curvature, a noise/static overlay and a darkened vignette around the edges. The scanlines and the noise are animated over time to feel more realistic: set their speed and frequency properties to 0 if you prefer a completely static image.
Reference
All effects are listed in the effects reference page.