Paladins can easily beat Warriors because part of their damage is Holy, which can go through the Warriors' high armor.
On the other hand, a Warrior is very good at defeating a Priest because they are immune to fear. Whereas a Paladin can easily be defeated by a Priest because the Priest can drain his or her mana, and then the Paladin cannot use his or her skills.
It really depends on what you want your character to do. If you want to dual wield two-handed weapons then pick a Warrior. If you want to be able to cast buffs on other people (e.g. hand of freedom, hand of protection) then play a Paladin.
Personally, I prefer a Paladin because of their Crusader Aura. It allows you to travel on your mount faster than any other class. It makes questing quicker, gathering quicker, and gives you an advantage in PvP Battlegrounds.
Hope I helped!