Your safe should be VERY difficult to move. Why? Because if you can move it easily, so can someone else. And if it can be moved, you've just packaged up all your stuff into an easy to steal package.
Your safe also should be not visible to anyone you don't want to see it. Yes, some safes have very nice outer finishes. Why? You're not buying it for looks, but for function.
You'll want active bolts on all four sides of the door, as well.
Aso, get more safe than you think you'll need. You'll grow into it. Trust me on this one.
I suggest the manual combination ones, as well. Yes, there are battery backups. Yes, the electronic ones might be easier to open. But why take the chance? I can get either one of my safes open in 15 seconds with the combination lock.
Finally--buy quality ONCE. No safe is absolutely burglar proof--but your average burglar isn't going to spend the time trying to get into a good safe unless they can smash it in quickly. Make it big, heavy and of good quality.
Hiding in plain sight...