There are just too many free Mac apps available to include everything. Though this list is long, it is by no means complete.
That's because some of the best apps in a given category are so much better than any Mac App Store counterpart that I couldn't exclude them.
I've included some apps that are not available in the Mac App Store. Since this is a list of apps, I'm not including services that only have websites without a dedicated app (there are two exceptions to this rule on the list, but they are totally worthy of rule-bending). VPN Deals: Lifetime license for $16, monthly plans at $1 & more