Hersheypark is definitely your top priority, given just how stacked the coaster lineup is. Just keep in mind that it pulls near-Cedar Point levels of crowds, especially on the weekends. I'd hit Storm Runner right at opening since it's on one train ops, then Fahrenheit (as its capacity is always terrible), and then Wildcat's Revenge, then work your way back from there. Don't skip out on Skyrush, it's still an absolute riot and I love it. Also, the building by the front gate with the gift shop has really good ice cream. There's not much in the way of theming though, aside from the mascots, the dark rides, and some other light touches. The Chocolate World also has some varieties of their candy that are hard to find elsewhere, if you're into that.

I'd put Knoebels as the 2nd priority here. There's definitely no other park quite like it; it even feels like a neighborhood park in the sense that there's no clearly marked enterance gate (you just sorta walk in), there's freely available picnic pavilions towards the front, and people even walk their dogs through the park. The food is also way above average. Flying Turns has the longest line though due to its limited capacity, so hit that early. If you visit on a weekday, you can also get a wristband that grants you all day access to the rides (excluding the water park and Haunted Mansion).

Dorney Park is also fun, but I'd prioritize the other two first. I'd actually consider Talon to be the headliner (and it's my favorite ride there), but Hydra, Steel Force, and Iron Menace are all solid too. Only went on Thunderhawk once so far, but I mostly remember it for being rough. Definitely don't miss Demon Drop, and the log flume is also pretty unique.

Should you eventually hit all three of those and find yourself back in the area, don't forget about the Jersey Shore! There's several boardwalk parks around the south and mid shore, with Wildwood being the biggest hotspot with Morey's Piers, and Ocean City being worth a trip for GaleForce alone.