One of the features JWST reveals so clearly in the Crab Nebula is the dense, spinning pulsar at the nebula's center. The pulsar isn't nearly as obvious in the Hubble image (on left).
Hubble Image: NASA, ESA, J. Hester, A. Loll (Arizona State University); Webb Image: NASA, ESA, CSA, STScI, T. Temim (Princeton University).
The high-speed jetstream can be seen around Jupiter's equator.
NASA, ESA, CSA, STScI, Ricardo Hueso (UPV), Imke de Pater (UC Berkeley), Thierry Fouchet (Observatory of Paris), Leigh Fletcher (University of Leicester), Michael H. Wong (UC Berkeley), Joseph DePasquale (STScI)