Define what you mean by "strongest type"?
Encryption protects the confidentiality of information in transit (prevents it from being read by a third party before it gets to the intended destination).
But to truly secure a message, you also need to make sure 1) that the person on the other end is really who you think it is and 2) that the message content was not modified in transit.
I'm guessing from your post that you're looking for the strongest encryption algorithms, and examples of products that implement them. There are many encryption algorithms that are strong enough for use today. However, even if a product implements the encryption correctly, it must protect the encryption key from side channel attacks.
I would check out Federal Information Processing Standard (FIPS) 140 as a reference, which specifies the algorithms and strength authorized for use by the US government. In a nutshell, use Advanced Encryption Standard (AES) or Triple DES (3DES). If you're not from the US, check out your government's sister standard as a reference.
If this doesn't go down the right path you need, give us more information on the depth and level of technical detail you need for this report.