I live in Bronx NY and have a choice to work at either the NJ office OR the NYC office. Which is better from a tax perspective alone ?

If you're a New York resident you will be responsible for New York taxes. No matter where you work.

What DonaldM says is true; you WILL be responsible for NY state and NY city income taxes regardless of where you work.

However, by working in the NYC office, you will NOT be obligated to file a NJ tax return to pay NJ income taxes. Your tax burden will not change (NY will give you a credit for the NJ taxes paid), but filing your state tax return will be MUCH simpler if you only have to file for NY state.