Also leveled both because I couldn't decide (lol) and I have to agree with many others
PLD is usually the safer bet and performs great on bosses like Titan. Also great if you have CNJ34 and MRD leveled.
WAR is generally more fun because you feel like you can dish out more damage and have more options. MNK42 and GLA34 makes it even more fun.

But their playing styles feel different. If you love being a tank, go both and switch whenever you feel like.