what is the best way to move one netsuite account data to another netsuite account... for eg: entity data, vendors, contacts, customers, scripts, custom forms?

What environment? a. PROD to SANDBOX b. PROD to PROD c. DEV to PROD

b..prod to prod

You could do the ff: a. bundle and install b. Export all data to CSV then upload it to the other account. c. Copy To Account - This is on Beta and not really sure how it works yet.