In my personal experience of playing in Hunger/Survival Games server, there are waaaaaaay too many hackers. Yes, you can get NoCheat or some AntiCheat thing, but that's not going to do a single thing against ChestFinder and forcefield. Yes, you can probably get more people on the Hunger/Survival Games server, but truthfully, the hunger games server that nearly everyone hears of is mcsg, and there aren't much chances with getting word out to much people besides people in this community, and mcsg, is just very horrible, It can be proven and guaranteed that probably 70 percent of the players of that server are hackers. I don't think any Walls or SG servers are going to be good.
In MineZ servers, its very easy to hack as well, also a hacking fest, it can also be easily griefed.
If its' just endless dungeons, that would be very very fun, but then it'd soon get boring once you achieve all the high tech armor and swords.
I propose an idea (very much like Infinite dungeons). What I have in mind is traveling to different maps. each map having its own shares in monsters, as you progress through the game, you can have a level up system, and stats where you can improve your far range shots, melee shots, speed, dodging attacks. You can level up by fighting players, there will be towns in every city, every city is a safe zone, once you leave the cities, you just travel fight mobs, learn experiences, get gold from killing different monsters, different maps have different monsters, as the game progresses, the maps start getting harder, places to rent and build a house, of course you can travel back to every map.