i'm from out of town and have been fortunate to hit the parks usually on a start of a tuesday.
for me, i have not experienced large crowds at the parks on a tues, wed, thurs.
all weekends are busy at any park.
disney, six flags, busch gardens, universal, sea world.
i stay on site and avoid the lines for rides with the fotl.
but, that still gives me lines for getting thru crowds on the walkways, the rest rooms and food places.
if you go on a weekend, go early.
eat at off times such as lunch around 11ish, dinner 4:30 ish or 7ish in the evening.
if you go on a 3 day weekend, expect a tad bit more crowds.
it is a hit or miss on the crowd question.
a lot of it depends on the date and time of year you go to the parks.