Self-promotion
Popular sizes, not all of which have even one image in that size:
- 88×31 (late-’90s button)
- 240×60 (newfangled indie-site size)
- 728×90 (late-’90s banner ad)
- 300×250 (mobile, nonstandard)
All of these are in pixels, not points. Double each dimension for proper Retina-tier images.