That question is highly subjective. I think the best you can get are people's opinions on jobs they enjoy rather than discovering a best/worst job.

I will say that the most poorly conceived job is probably PUP. SE created this job with a seeming lack of foresight which almost immediately doomed it. It is now the object of the most ridicule in the community rivaling that of DRG and DRK.

As for best... I will say that my favorite is BRD. I don't feel that any other job offers all that BRD can offer. BRD can make a pretty serious tank in many situations. They also can pull for merit PTs in a way that is unrivalled. I find it exciting because unlike low level XP it is extremely fast paced and the mobs are only alive for 15-25 seconds so you have to take care of so many things very quickly. BRD can also make for a passable back-up healer. About the only thing BRD seriously lacks is the ability to do much damage.

I would never feel as safe on another job as I feel on BRD. I have the ability to sleep mobs around me uninteruptably and without risk of magic aggro or worry for MP. I feel truly in control as a BRD.