A web wallet is one such wallet. You do not need to use any additional applications to save it. It is much safer. In my opinion, web wallet is much better than mobile wallet. Using it does not require a separate space. Hopefully the wallet will expand further in the future.
Most web wallet are centralized in nature so it'll just be wrong chosing them general over mobile wallets. With mobile wallets you are in charge of the welfare of coins to some extent as even with the centralized wallets, you'll still need to be very cautious to avoid corrupting your device and give access to viruses to steal your coins. Web wallet are the closest to hardware wallets which are the most recommended form of storing your coins. They're very affordable that you got no excuse to choose web or mobile wallet over them.
But since the discussion here is focused on just this two types of wallet then my vote has to go to web wallet and the recommended one to patronize should be electrum. It has all the advantage a proper wallet should have excluding the extra security a hardware wallet has.