Through my years of mmo and rpg gaming I've tended to swing between the two extremes of the warrior/wizard dynamic.
Some days I just want to be a dumb tank in full armor soaking up hits and acting as a wall for squishier classes. But then there's days where I love being a glass cannon that can kill something in 1-2 nukes but a strong breeze can kill me.
The least fun I've head with a class was as a healer druid in Everquest. Something so stressful about the party relying on you for heals and if you wipe it's generally your fault. idk how people dedicate themselves to a class like that.
I'm a bit of a number freak so I just gravitate toward whatever lets me stack a ton of modifiers and mechanics that multiply each other and cause crazy numbers to appear on the screen. That usually means mage characters that exploit lots of status effects but also can mean warriors that use every buff effect or similar things.
My favorite Path of Exile character was a build that would stack strength and int. Strength gave life, damage multiplier, and energy shield multiplier; life was converted to energy shield; int gave energy shield multiplier; energy shield then was converted to a sword. My spell damage scaled with triple the damage of the sword. Any small tweak I made to improve the build ended up giving huge gains just because of how much it would get compounded across all those things.