What type of Minecraft Server is best to use?

Thinking about starting a server in the near future. Knowing this, planning needs to begin. I need to know what type of server is most liked among the Minecraft Community. Factions sounds like one of them but there are a lot of faction servers. Mods on Forge Dependent Servers (mods like Pixelmon for example) also prove to be in great demand to many. What should I do for my beginning server if I put one up?

Survival is pretty popular, but make the ranks like 5 or 10$ if you want to get a LOT of donations (if that's what you're looking for). You should also have good plugins and listen to what the players want.

I ran a server from 1.7.1 BETA to 1.4.2, and this is what i found based on my user reviews.

They liked ideas of factions, but it is wise to keep factions from exceeding ridiculous levels of players as it sort of ruins the fun for smaller factions. Also, a money system was in high-demand on my server, as well as fun plugins (More-or-less plugins that make the game more interesting rather then really game changing. Plugins such as mob grinder, torch-light, etc were all loved by my players.) and they REQUIRED essentials to play at all.

Really, start a basic server with essentials, factions, and PermissionsEx, and watch, listen and act on what the players want from you as plugins.