Information-theoretic security From Wikipedia: 


  Information-theoretic security is a cryptosystem whose security derives purely from information theory. In other words, it cannot be broken even if the adversary had unlimited computing power. The adversary simply does not have enough information to break the encryption and so the cryptosystems are considered cryptanalytically-unbreakable.


List of unbreakable encryption-methods:


Secret sharing
Private information retrieval with multiple databases
Reduction between cryptographic primitives or tasks
Symmetric encryption with high entropic security
Quantum Cryptography


Why quantum cryptography isn't commercially used:


  GCN Article: “There are limitations to QKD (= Quantum key distribution),” Hayford said. Photons can only be sent about 60 miles, and it is a point-to-point protocol, meaning that complete system hardware is needed at each location. Expanding a system beyond a campus or a small number of local facilities “starts to be a little impractical.” And: "There also are challenges with existing hardware, particularly in the generation and measurement of individual photons. “That is a complicated physics problem,” which NIST and other research facilities have been working on for years, he said. Ideally the photon source would generate a single photon on demand. “We can’t do that right now.”
  
  The problem for a broad execution of QKD is, that the two parties have to know each other before communicating. And there needs to be a physical established line of communication, either from point to point or in nodes.


One-time pad
Pedersen commitments against the opener
ElGamal encryption used as commitment, against the committer


My questions are:


Are there more known unbreakable encryptions? If so, please provide a link &amp; I will extend the list.
Why aren't these schemes commercially used? Please provide an explanation (and link if possible) and I will edit the list as well.
Information-theoretic security is a cryptosystem


Nitpick: information-theoretic security is a property that a cryptosystem can have against a particular attack model. AES is a cryptosystem, but doesn't have this property against any of the usual models; the one-time pad is a cryptosystem that does against passive attackers (but not active ones).

Other systems that have information-theoretic security, off the top of my head:


The one-time pad, against passive attackers.
Pedersen commitments, against the opener (but not against the committer).
ElGamal encryption used as a commitment, against the committer (but not the opener).
A bunch of OT systems of the Chu-Tzeng style, against either the sender or the recevier (against both at once is impossible - same goes for commitments).


Some of the above schemes are very much commercially used. 

QKD is a very specific form of quantum cryptography, the two terms are not equivalent.