@lResxt yeah agree. I though i can add more later. At least 10 or 15 maps. Including the Sanchez78's Der Riese mod, which have a big improvement with guns, perks and a good Easter egg), UGX Requiem, Rainy Death and many others that i know the people/casual players gonna love.
Installed Plutonium 3/4 days ago. I saw some ugly basic maps in the most of servers (saying as constructive criticism, don't get it wrong lol). I know theres hundreds of custom maps and is too difficult and boring to search one by one what maps are better than others.
Longstory short. I will suggest at least some of this maps. I consider this maps could be at the same level design as oficial treyarch maps. Or even better 
1. Industrial Estate (T4M/BO3 Update).
Description: Nova crawlers (teleporting, EMP, jumping, kamikazes), Juggernaut Bosses, BO1/BO2/BO3 Perks, 3 hit without Jugg, buildable Zombie Shield, Buildable Sliquifier, Baby Gun, BO3 guns, and more.
Link for more map details: https://www.ugx-mods.com/forum/map-releases/29/industrial-estate-t4mbo3-update/7842/
2. Encampment Version 1.
Description: Jungle theme and atmosphere, weapons from COD Series and BF4, Dual Wield weapons, 9 randomly spawning perks (like Shi No Numa), buildables; Power, Zombie Shield and PaP, Shrieker zombie, Origins and Shangri-La zombie models, The Scavenger, Ray Gun Mark II Blundergat and more.
Link for more map details: (Same Link for Encampent Version 2 BO3 mod): https://www.ugx-mods.com/forum/map-releases/29/encampment-v2-black-ops-3-mod-t4m/9641/
3. Encampment Version 2: BO3 Mod
Description: This is a huge update for the map "Encampment Version 1". Lots of Black Ops 3 Weapons added, 3 hit without Jugg, BO3-Like HUD, including Round Counter, and Point Counter on the left, Remapped some areas of the map, a New Special Round - Spiders from Zetsubou No Shima. Apothicon Servant, and more
Link for more map details: https://www.ugx-mods.com/forum/map-releases/29/encampment-v2-black-ops-3-mod-t4m/9641/
4. Project Contamination: Awakening
Description: This is a remake of both Shipment and Vacant, fused into one map, with a lot of new areas to explore. Guns from MW2 up to BO3, Battlefield 4 and Survarium. Buildable Sliquifier, Galvaknuckles, Gersch Device, C4,11 perks, and more.
Link for more map details: https://www.ugx-mods.com/forum/map-releases/29/project-contamination-awakening-version-1-1/9927/
5. Kino: the Rebirth.
Description: A remake of the fan favorite map Kino Der Toten. It has been redesigned with a futuristic theme, custom weapons spanning MW2 to Ghosts, and an Easter Egg.
Link for more map details: https://www.ugx-mods.com/forum/map-releases/29/kino-the-rebirth-final-release/8435/
6. Oil Rig (BO3 mod Update).
Description: This map is a re-imagining of the MW2 SP mission 'The Only Easy Day... Was Yesterday'. Nova crawlers, 3 hit without Jugg, Juggernaut Bosses, Panzer Soldats, BO1/BO2/BO3 Perks, buildable Sliquifier, QEDs, Gershes, Venom-X, Super sprinters, BO3/BO2/BO1/AW/Ghosts/MW3/Titanfall guns
Link for more map details: https://www.ugx-mods.com/forum/map-releases/29/oil-rig-t4mbo3-update/9134/
7. Der Berg.
Description: This map is based on Der Riese. Default Der Riese features, BO1 guns, mule kick, stamin-up and Electric Cherry (which can only be acquired by completing a simple easter egg), changed character voxes, altered gameplay dynamics (sounds, fx etc.)
Link for more map details: https://www.ugx-mods.com/forum/map-releases/29/release-der-berg/14768/
I hope the Server Hosts see this suggestions so more casual people can enjoy this masterpiece maps