What works best in a grid down situation?
I'm not going to lie. You get the best bang for your buck from a generator. A generator big enough to run a freezer and an AC unit can be had for less than $500. Enough solar electricity to do the same job will cost you thousands.
If all you are concerned about is having enough backup power to last a few days, by all means, get a generator. Make sure you know how to use it safely. Gas storage, electrical connections and carbon monoxide poisoning are all serious issues that must be dealt with.
Where a generator starts to fall down is during a long term outage. Storing fuel for weeks or months worth of use is not cheap. It's also probably prohibited by your town's safety codes. There are reasons for that. Bulk fuel storage is a specialized operation requiring proper equipment and training.
So how does solar stack up long term? The best part of solar electric systems is the fact that they just work. No need to tinker with them. No handling fuel. They are quiet and reliable.
What kind of system do you need? Like everything else, that depends. Ideally, you have a system on your house that pays for itself day in, day out. When the grid goes down you might not even notice as the system smoothly goes to battery backup. Now some worry that roof mounted panels could be damaged in a hurricane. True, but your roof will probably be flying off at that point and you'll have greater problems than a lack of electricity. Some people have had success with temporarily removing the panels and tossing them in a swimming pool for safety.
Even a small system can make a huge difference in your quality of life. A 100 watt panel, deep discharge battery, charge controller, and a small inverter costs no more than a cheap generator. It won't power your freezer, but it will charge your phone, keep a light on, power a fan, and do other light jobs. It will also do it long after your neighbor's generator has run out of gas.
If you've got an RV or a travel trailer, or even a van, you've no excuse not to have solar mounted on the vehicle. It makes dry camping much easier. You can drive the vehicle out of harm's way. When you get back to your home, you have a power source available for fixing your house.
Another option is to build a power trailer. Take a cheap utility trailer, mount a battery bank, panels, and associated electronic and you are good to go. These are great where there are ordinances against having solar panels on your roof. I know people in that situation. They park the trailer in the driveway or behind the house and snake a power cord to to the house to run a few items year round.
This power trailer was built to power concerts in areas beyond the grid. It has better quality electronics than most because it powers high end audio equipment.
The thing with generators and solar, it doesn't have to be an either/or situation. They can work well together. For example, a generator might be run for just a few hours a day -just enough to keep the freezer cold and to cool the house down a bit. The solar electric system runs full time to power lights, a radio, and charge electronics. That stretches out your generator's fuel supply.
Waiting for the grid to come back up is a terrible feeling. It's even worse when you have no power at all, your phone is dead, and radios don't work. Backup power can be a life saver, and it always provides some peace of mind.