HDFC is the worst. Avoid them. Lazy morons, and technically challenged. You would be required to visit their branch for almost everything. Even trivial things like changing email address, phone number or address. Their customer care is available only till 8 PM in the evening. Jokers.
For online transfers, best account today is ICICI B2. Zero balance, FD interest rates, and unlimited free NEFT transfers. Downside is that this is a branch free account, and there are some weird pin code based restrictions on which addresses are supported for opening an account - God knows why they would put such a restriction on an online only account. You also do not get a branch access, or an ATM card for that matter.