I purchased a home closet safe about a year ago. Here are some things to consider:
Safes are rated for three different kinds of peril: Burglary, Fire, and Water. Each category has a different rating system.
Most of the "safes" sold for use in the home are classified by Underwriter's Laboratory (UL) as "Residential Security Containers" (RSC) not "safes". Many, but not all of the safes on the market are approved as Residential Security Containers. Look for the UL label on the safe to see if one you're considering is UL approved as a RSC. A RSC is not as burglar-proof as a true safe with a UL "tool" (TL) rating. A high-end safe might have a TL-30 rating for example. This means that it will protect the contents of the safe from a motivated thief with appropriate tools for 30 minutes.
The vast majority of home safes will not have a UL or Intertek fire rating. Home safe manufacturers like to point to the RSC approval label and say it "pass UL testing". This is a lie. It only means it passed UL testing as a RSC. It says NOTHING about the fire rating. Most manufacturers "self certify" their safes for fire. For example, a typical safe may have a "rating" of 60 minutes, at 1200 deg F. This means that it will supposedly keep the interior below 350 deg F when exposed to a 1200 deg F fire for 60 minutes. I haven't done any testing on my own, but as an engineer and a certified skeptic, I think most of the home safe manufacturers are playing games with this testing. For example, they may lay the safe down on it's back during testing or place a container of water inside during testing. UL doesn't allow these cheats. If you see a safe with a UL rating for fire, you can be relatively certain it was properly tested. If you don't see a UL or ETL (Intertek) label showing the fire rating, you can assume the manufacturer exaggerated the claim.
Water ratings are rather rare. A few of the lightweight Sentry safes are rated for water, but not many others.
I ended up getting a Liberty Premium 20 safe (http://www.libertysafe.com/safe-premium ... ps-19.html
), mostly because it was the only one I could find that would fit in the upstairs closet. I believe the 60 minute, 1200 deg F fire rating is optimistic as there are large holes in the sheetrock insulation for the hidden hinges. I have it screwed to the floor and it weighs 630 lbs so it would take a determined thief to get it open, but I'm certain it could be done in less than 30 minutes with an angle grinder and diamond blade. I liked the fact that the Liberty safe uses an S&G Titan D electronic lock. In my judgement I believe this design to be more reliable than other electronic locks that use a motor to actuate the lock mechanism. I bought a lifetime warranty on the lock just in case.
I was rather put-off by the fact that the label in the Liberty Premium 20 didn't agree with the manufacturer's datasheet in some areas like the gauge of the sheet-metal body and by the large holes in the insulation to accommodate the hidden hinges so I bought a Champion SS-12 for my sweetie for Christmas 2011 (http://www.championsafe.com/products_supershort.html
) . It is smaller and lighter than the Liberty Premium 20.
In my experience virtually ALL of the home safe manufacturers are a bit sketchy. The label on my Liberty shows 11 gauge sheet-metal for the body, but I measured it and it's 12 (thinner). The literature for the Champion including their website shows internal hinges, but the safe that showed up has external hinges. I bought lifetime warranties on both of the electronic locks but had trouble getting documentation from the manufacturer that I had the warranty. They kept saying it was "on file". Not good enough for me. It would be easy to "accidentally" lose any record of my warranty when it came time to pay a claim.
Costco often has sales on decent home safes. The Bighorn series appear to be better than the Cannon series, but YMMV. The Bighorn 19ECB (19 cubic feet) is often on sale for $569. That is a very good value.
In my area, the safe dealers advertise on Craigslist. They seem to be sold by "moonlighters" that have large acreages in outlying areas where they can put large barns for their showrooms.
The Sentry safes that are sold just about everywhere are very flimsy. I could open one with a crowbar in 5 minutes. You'd be better off with the Costco Bighorn 19ECB than a Sentry in my view.
I also have a safe deposit box that contains things I really don't want stolen, like my Grandfather's pocket watch.
A few things: I safe that isn't bolted to the floor with strong screws is just a nice box that will help the thieves carry everything out in one big load. Also, you really can't rely on a safe to store magnetic media, like floppy-disks, hard-drives, etc. Remember that the fire rating of a safe is specified to keep the interior of the safe below 350 deg F. This is because paper will begin to yellow at 350 deg F. Magnetic media will be toast at MUCH lower temperatures. If you're concerned about keeping your digital data safe from fire, invest in an offsite backup service. I recommend CrashPlan. My brother backs his data up to my computer and I backup to his using CrashPlan.
Here's my conclusion: If you're willing to spend $1500 or more on a safe, you will get a decent level of fire and burglary protection. If you're not willing to spend $1500 you'd be far better off with a safe deposit box. Safes will not protect magnetic media.