What is the safest kind of lock?

Answer 1

There are many quality locks out there. Really good ones are generally classified as "high security" because they feature hardened metals, superior construction, and non-standard locking cylinder which are not the standard "pin tumbler" design you probably have on your house now.

In the United States, there a small handful of major competing high security lock manufacturers:

Medeco

Assa

Schlage Primus

All of these have strengths and weaknesses. All of them are, to varying levels, more difficult to pick than standard locks. They are all mechanical locks though, and therefore can be picked (although with great difficulty, not something a burglar is going to be doing). I say this because any locksmith that tells you the lock he carries is "pick proof" either doesn't know what he's talking about or is lying - two things you want to stay away from.

Medeco has an excellent range of decorative residential hardware, great for most homes. Medeco is the most popular high security lock in the United States, and makes a really high quality product.

Assa features a locking mechanism which is very secure, however Assa is mostly geared towards commercial customers.

Schlage Primus doesn't have the same range of high quality decorative hardware like Medeco has, but has the added advantage of being fairly easily integrated into existing Schlage systems in commercial complexes.

High security locks are expensive though! Plan on spending at least $150 on a deadbolt.

Source:

http://www.locksafesystems.com