Mine are a bit subjective but the main thing I look for in a class is flexibility and choice. I hate being locked into a concept
Oracles: Revelations and curses keep it feeling fresh every time. Please paizo release some more curses though
Barbarian: Despite the amount of AM SMASH Barbarians there is some nice variety in the class
Witch: Hexes make the DM groan and party cheer
Bard: I'm helping!
Medium: Like I said I love flexibility
Shaman: Well I like oracles and witches and flexibility so I feel this is a gimme
Alchemist: Hehhehehhehehhee! Booom!
Kineticist: Like the flavour and with constant drip feeding of ability choices I always have something to look forward to
Inquisitor: I always have the right tools at my disposal
Cleric: All your choices are done at 1st level other than spells and feats you never change
Magus: For the love of God can we please stop having shocking grasp scimitar magus
Gunslinger: Not a fan of guns and if you don't want guns then tough luck with this class
Fighter: If I give other classes crap for only giving feat choices well then...
Swashbuckler: Like the gunslinger it is locked into a concept and stuck there hard. It is good at it but gets little else
Vigilante: Great flavour but damn is it hard to work into any campaign that isn't stationary
Antipaladin: Welp there goes the party
Hunter: Doesn't have enough unique features to make it worthwhile. Teamwork feat list pretty much means it needs to be melee.
Summoner: Just too damn strong and most I have encountered run exactly the same character.
Cavelier: Wait several of my class features rely on my mount why are we constantly in dungeons with 5 ft corridors!