Also; some sites still haven't learned lessons regarding background choice - be it texture, contrast or issues that only show up when scrolling/in particular browsers.
Things I've noticed on some blogs/sites - "vibrating" columns, where moving the mouse over the area causes it to judder up and down by a pixel or two. Has an unnerving effect similar to a picture taken deliberately out of focus...
Another is using dithered (I think that's the right word) colours for backrounds... Fine when stationary, but combine with an LCD screen that has a distinct refresh rate and scroll down and all of a sudden you have juddery nastiness again.
Never mind the good old grey text on slightly different grey background.
Or long winded posts written in very ornate fonts. yuck.
Aaaaaah. That was cathartic.