Matt, I went through this awhile back. There are some great summaries online of what to look for, for example capacity, height, fire rating (as if your guns could be safe if your house burned down), bolt mechanisms, electronic vs mechanical combo lock, weight of the unit, wall and door thickness, hardened casing on the lock, , made in USA, etc. there was a great thread last year on the forum, I'll look for it. I ended up buying from West Coast Safes in Ontario. They delivered it, leveled and bolted it in place. Give some thought to where you'll place it because how you position it is at least as important as any other factor in preventing theft. If thieves can get a safe on its back, just about any safe can be opened in minutes.
I bought my safe to keep my firearms away from unauthorized users; I decided not to worry about fire and professional thieves. Personal choices. Just know your objectives for the safe, because it will clarify the options for you.
http://www.westcoastsafes.com/