Monero CLI wallet is the only reasonable and well tested option we have to store larger amount of XMR although the new beta graphical wallet (GUI) is out too. Finally something user-friendly.
The promises of upcoming Monero hardware wallets are for now just promises.
Trezor now added native support for DASH and ZCASH - and explained what the altcoin needs to get supported (looking at you, Monero).
Where to store altcoins? See a list of altcoin wallets, from web based wallets to best hardware wallets.