My honest opinion will say bitcoin core, but if you are worried that it takes up too much space, then blockchain.info. If you are scared of the internet, use Electrum.
Right now I use a Ledger wallet. It's basically a cheap and reliable alternative to a Trezor.
yes bitcoin core so far is the best,with so many deeloper that keep developing bitcoin wallet,now has so many bitcoin wallet with better security.
but bitcoin core which create by satoshi is still better,this article said like that
http://www.hongkiat.com/blog/bitcoin-wallets/and i sureprise why OP not add coinbase and multibit in poll.