Owlbear Rodeo is very simple to use, and you can get up and running really quickly. The base game is free, but the upcoming 2.0 version will charge like $3.50/mo for storage if that is what you want (you can also just store the maps locally and upload them when needed if you don't want to pay). It has basic fog of war but not the dynamic lighting that more advanced systems use. It would be the first thing I recommend checking out because it is free and easy.
Fantasy Grounds is great and if you are just using it offline as a map tool to project to a screen I believe you can use the "Demo" version which is free. You only need a license if you are connecting to other computers on the internet. So this is the cheapest way to get the dynamic lighting feature. I has a bit more of a learning curve, but lets you set up line of sight blocking, light sources that are static or attached to tokens, toggleable doors, etc. So all the bells and whistles you could want, but I will take some learning to get it working to its full potential.
Roll20 has a decent free version, but you have to pay the annual sub to use the dynamic lighting. So in the end it will be more than FG if you want the advanced features. It also requires a bit of learning to get all the features working.
I have not used Foundry, so can't comment one way or another.
Fantasy Grounds is great and if you are just using it offline as a map tool to project to a screen I believe you can use the "Demo" version which is free. You only need a license if you are connecting to other computers on the internet. So this is the cheapest way to get the dynamic lighting feature. I has a bit more of a learning curve, but lets you set up line of sight blocking, light sources that are static or attached to tokens, toggleable doors, etc. So all the bells and whistles you could want, but I will take some learning to get it working to its full potential.
Roll20 has a decent free version, but you have to pay the annual sub to use the dynamic lighting. So in the end it will be more than FG if you want the advanced features. It also requires a bit of learning to get all the features working.
I have not used Foundry, so can't comment one way or another.