Seychelles is a great place to form IBCs because it has a fast and reliable registry, formation and annual fees are relatively low, and the service providers are very keen to help and are very professional. Depending on your exact requirements you can have a Seychelles IBC for less than the BVI government fee and it can be ready within 1 day.
However, the “best” jurisdiction will largely depend on your specific requirements. Seychelles is good if you require a general-purpose IBC, particularly if you want a low cost holding company or an special purpose vehicle.
If you will have very complex financial transactions and arrangements and you will require the sophisticated services of lawyers or accountants in places like London, New York, other offshore financial centres may be more viable. It can also be more challenging in some jurisdictions to open a bank account for a Seychelles IBC.