This has been YEARS ago (like...close to 20

) but our experience was that if you want to go on the big coasters, you have to plan for multi day, whereas if you're a wimp like me and just want to do the little stuff, you can do lots in one day. We went as a large group and those who wanted to do the big coasters stood in line 3-4 hours for each ride and only did 2 or 3 rides. I did tons of stuff and never waited more than a few minutes.
Now, I recognize that things change, and there are new options like buying fastpass type things, so this information is probably very outdated, but I wanted to share anyway.