There's no sort of "rank". There are a few good wallets, but which is better depends on the user. Wallet A might be better for me, while wallet B might be better for you. It depends on personal preference.
Anyway, if you're holding huge amounts of bitcoin or cryptocurrencies in general, as always, I heavily suggest purchasing a hardware wallet like the Trezor[1] or the Ledger Nano S[2] if you're not tech-savvy enough to properly and securely make a paper wallet, or an air-gapped device. Among the two, I personally prefer the Ledger, but yea, personal preference. I suggest doing research on both devices for you to decide on your own.
If you don't hold much bitcoin, like probably sub $500, a mobile wallet like Mycelium[3] should be enough. Just make sure to store your private keys OFFLINE. Not on a note file, not on you email, on Facebook Messenger, etc etc.
For more information about wallets in general, just so if you haven't read much on these yet:
[1]
https://trezor.io/[2]
https://ledger.com/[3]
https://wallet.mycelium.com/