Paladin is cool because it is the only tank with a ranged part of it's rotation.
Sick of boss mechanics making you move away and just spamming Tomahawk? Time to get that big dopamine by adjusting your rotation so you can keep the pain going while laughing in the bosses face.

Also, PLD has the only "true" invuln. Hallowed Ground is a monster and will make you laugh in the bosses face even harder.

Also, because it has an offhand weapon it's glamour game has some interesting creative space you don't really get from any other class in this game.
(well, some mages had this creative space, but lose it after levelling out of ARR).

Paladin is also one of the two tanks with the most defined rotation (other being GNB), so once you get the hang of it it makes for a real smooth prog class (especially since it has a lot of useful tools to keep parties from falling apart) and very enjoyable to try and optimize.