Define "hassle."
If you're a resident, you'll need your cedula and residency card.
If not, you'll need a passport, a letter from your home bank, and possibly a letter from an account holder at that bank.
Virtually all the major banks have the same policies, so it's your choice.
With all due respect, I disagree: The policies might be the same (this you can compare on their websites), but practices not.
As stated many times in this forum, it depends on the branch, even on the person attending you. To avoid "hassle", best is to avoid touristy places, there the requirements might be more complex, and dress appropriately, as you would back home.
I have opened multiple accounts in two banks, BHD Leon (when it still was just Leon) and Banreservas, never provided anything more than my passport and the opening amount.
I think ScotiaBank is famous for requiring quite a lot.