Which is the best certification for Project Managers in Dubai/Saudi, PMP or Prince2?

It depends on the projects you're working on. Probably you'll have to start with some PMP training anyways.

PMP is most famous is Saudi Arabia

Now the PMP has become overly addictive to Saudi Arabian market. Thou it is an awesome and best or I can say a must have Certification, Prince2 is good at its best.

To conclude, Saudi Arabian market is slaved to PMP, go for it.

Most of the employer look/perfer for the PMP certification.

The PMP certificate then MBA.

PMP is most famous is Saudi Arabia

AND Most of the employer look/perfer for the PMP certification.

Thanks for the answer, I would like to know in Saudi what will be preferred most

The PMP Certified People is more qualified. 

PMP is valued more but value always counts for CISA/CRISC professionals