My friends and I recently challenged each other to list our top five starship classes and were surprised by how different our opinions were despite being generally in agreement with what we like about the various series.
Personally it was hard for me to make a definitive "top five" but here are some I rank highly in no particular order:
TOS-era constitution
Refit constitution
Discovery-era Bird of Prey (OG is good too obv but I love the HR Geiger-esque weirdness)
D'Kora class Ferengi ship
Not canon, but I love the original "Long-boi" Discovery design. It gives off some very cool art-deco retro-futurism vibes. Not very classically "trek" but I love it nonetheless!
Literally how the Constellation class got its name.
The Stargazer was originally a Constitution II-class starship and would have reused the refit USS Enterprise model from the first four Star Trek films. However, it was decided after the episode was filmed to change it from a "Constitution-class" starship to the similar sounding "Constellation-class" cruiser. This was so that when LeVar Burton dubbed over the line, the new dialogue would closely match his lip movements on screen. Wesley Crusher says the ship class when making his announcement on the bridge; his lips also appear to say "Constitution". Data also mentions the ship's class by name when reading from the dedication plaque, but his back is turned to the camera; when he says "Constellation" the closed captions say "Constitution."