Between the old flavour quests for our abilities (going into Ghostlands for Redemption (so sweet) and the Blood-Tempered Ranseur (loved that model to pieces), the engaging game play (even though refreshing seals was cumbersome it kept you in the game, rather than being bored in your seat), and your contribution to your group (BoW, BoM, BoK, BoF, BoS, DI, LoH, aura twisting, RF and picking up when the tank died) the class just seemed so whole to me.
I quit in 3.2 though, came back late 3.3 on a new account on a DK and then later as a Priest. It took some getting used to but I am starting to enjoy the Cata redesigned Paladins. Definitely going to have this Paladin as my main for a long time(All 3 roles on 1 character (who needs Ranged DPS anyway!?) is a great perk).