I own an American Security ("Amsec") BF6032HD. It is the biggest gun safe I could fit in my place (narrow doorways are a curse).
My advice would be to get a safe bigger than what you think you need, get a safe with a really good fire protection rating, and bolt your safe to the floor.
An RSC ("Residential Security Container", basically a locked metal box - all gun "safes" are actually RSCs unless they are tool-rated) really needs to be bolted down to something that's not going to move. While gun safes seem absurdly heavy, even full of guns a motivated thief will have no problem carting it off. My RSC weighs 1100lbs and the delivery guys got it in the house in no time with a refrigerator dolly to get it to the front door and 2 small pieces of PVC pipe to wheel it around the house like the Egyptians did the pyramids, and they cared about not damaging my house in the process. A thief won't be slow and careful not to damage your things on his way out with your gun safe.
That being said if they're not going to just cart off with your safe, the most common way to attack an RSC is to tip it on its back and then pry the door open. RSC manufacturers like to tout how thick their door plate is and how many bolts they have but physics wins every time. There are some videos on youtube of how it's done. If nothing else, it's interesting. If a couple of guys with long pry bars can get a gun safe open in a few minutes without breaking a sweat and not being particularly motivated, a couple of guys trying to not go to jail/get shot by an angry homeowner are going to be in and out in no time.
I know this all sounds crazy, we all expect that if we do get robbed it's going to be some druggie smash-and-grab looking for easy stuff to pawn but you never know. Maybe that druggie realizes you're gone for the weekend and brings friends, or maybe a pro thief casing your area notices you have an NRA sticker on your truck or whatever, and comes in looking for guns while you're on vacation and is prepared to deal with an RSC.
Ultimately an RSC/gun safe is a small part of a multi-layered security system. Watchful neighbors, cameras, alarms (including the 4-legged kind), physical security (door locks, thorny bushes, and flood lights), and safes/RSCs all work together to deter a thief.