Indeed. But I think that towny is more passive and allows for creativity while factions is more of a defensive and offensive. But I would like to see towny implemented in the near future.
we can also say that the following are not unique
Survival Games
Draw It
Skywars
Some other possible ones on smaller servers would include
Creative
Skyblock.
well, if I bought a cow spawn egg and I didn't want it. Can I return it for 32 glowstone or keep it as a storage, but with heads, save for next season if you're still around.