I'd go with bank, if it's a simple deposit type account. If you have a debt security account (bonds for example), then there's the obvious choice on the drop down menu.
It's good that with this new form, you can save and simply rename for 2014 and subsequent years. If you're a candidate for checking 15a and really don't open/close many accounts, life is easy going forward. Ok, you could do the same with the old .pdf, but I'm liking the new layout and gave positive feedback to FinCEN when they approached me last month. Lets hope they don't make a revision too often though!