To keep bitcoin safe and avoid the high transaction fee and for all other best benefits which wallet we should use?
Which wallet is best in all means?
Electrum is good for use. Because you can change the transaction fee after sending the transaction.
I will also suggest blockchain. They have add a new system while sending transaction on their mobile wallet app. You can set the fee as satoshi/bytes for this new system. If you pay proper fee you don't have to worry about the confirmation of the transaction.
But I think you can't avoid the high transaction fee at any wallet now.