Armory is a desktop bitcoin wallet that is open source and multi-signature. It is a well known and reputable brand, and is a leading company in the field of Bitcoin security. They provide a cold storage option, where users can store private keys offline.
The interface can be difficult to use and it is not the best option for beginners, but it is regarded as one of the most secure bitcoin wallets available. Armory has some of the best security features of any desktop wallet. It has multi-signature support and decentralized storage, that give users full control over their cryptographic keys. Armory allows users to secure multiple wallet addresses so that they can easily store bitcoin for different accounts.

Copay is a hierarchical deterministic (HD) bitcoin wallet that was created by Bitpay. Copay is a great open sourced option for businesses because it is multi-signature, which means that a single wallet can have more than one user. It can be set up to require multiple signatures to secure a transaction. It is easy to use and is a good option for beginners.
Copay is available on desktop, web and mobile interfaces, allowing multiple options for wallet access. Copay has strong security features and is also one of the first bitcoin wallets to support the entire Bitcoin Protocol.