Ohhh... It isn't an easy question for me.
First of all, every single class is really funny to play.
So let's analyze each of them.
Warrior has a lot of weapons (swords, spears, etc.) making playthrough for him ins't a big problem.
The beginning... Hardmode... Celestial Event... Warrior always is cool!
Also, he's got the best number of defence. But the damage isn't cool unlike ranger damage.
Defence: the best. Damage: middling. Number of weapons: the best.
Mage isn't cool at the beginning, but since
Metor Armor + Space Gun he becomes probably the best class for this game stage.
At the ending of Pre-Hardmode he's still supercool class. After getting the Hardmode he's still a good one.
Since Hardmode to Pillars, this class didn't bring me problems. But Moon Lord... With mage low defence he isn't easy.
However, if you can farm Moon Lord, you will get end-game mage gear, that deals insanely crazy damage!
Defence: low. Damage: the best with end-game gear. Number of weapons: middling.
Ranger is a great class for beginners as well as Warrior class. At the beginning he cans easily craft a bow and arrows, this game stage isn't a problem for him.
As well as Warrior, he always is a pretty nice class. Also I think these weapons are UNREAL powerful:
Chlorophyte Shotbow, Megashark, Daedalus Stromblow, Phantasm (at my opinion, it's the best weapon can be obtained before Moon Lord), S.D.M.G., Tsunami.
Defence: middling. Damage: the best before the end-game. Number of weapons: a lot.
Summoner... The worst class for the beginners I guess. And the weakest, yeah.
But... If he is really is. Why do we need him?
And yeah, even the worst class in the game has got some applications
1) AFK farm.
Build an arena, where the mobs will spawn, but your character will be in safety. Summon your minions and go to the kitchen to drink a tea (and eat cookies, of course).
2) Special for Yrimir-like people.
If you get bored to kill bosses for few seconds... If you get bored to find a weapon for your class in the first minute of the game...
You should play for the summoner! :3
3) In addition to magic/ranger/melee weapons.
Defence: the worst. Damage: the worst (though Xeno Staff and Stardust Dragon are dealing really big damage). Number of weapons: the worst.
My opinion is:
Ranger is the strongest class.
Warrior is the guy who can tank loads of damage.
Mage is the most interesting class.
Summoner is the hardest class and class for AFK farming.
What about the poll? I've chosen "
Mage - Magic", because he's the most interesting class for me and I like it!