Which type of a server is better?

I would say the best gamemodes are Skyblock/Factions/Survival if you're starting a new server I would go with Survival just because that's what a lot of people like playing, it's simple to setup and keep onto of it, once you start growing your server then add skyblock! I did this and my server is getting along really good I now have Survival/Skyblock/Factions/Modded/Mini games