1. Ascension: This map has been my favorite since the week it was released. I fell in love with it because it reminded me of Der Riese. I love the wide open areas and the huge story development and the mysterious feel it has. Tons of easter eggs, and it has my favorite easter egg song. This map changed zombies in many ways.
2. Der Riese: Much like Ascension, I love the story development this map offered and the general feel is just better than most maps. It's just the right difficulty and is perfect for both co-op and solo. Overall great map. And of course it introduced PAP!
3. Kino Der Toten: Love the simplicity of this map. It's not very fun on solo, but it's my personal favorite for co-op. This map really satisfied me after so long without new zombies. It honestly didn't change much for zombies, but it is just well-designed. Nova zombies suck though.
4. Verruckt: Surprise! I effing love this map on solo. running around with the trench gun and stg is as fun as it gets. The size makes it hectic but the design is perfect for creating trains without it becoming too easy. Overall the map is the perfect difficulty on solo, and a great challenge in co-op. Not to mention it's creepy as fuck.
5. Shangri-La: I like to call this map "The Polarizer". It took me a while to find my love for this map, but once I found the huge amount of strategies for it I became addicted. This map is good for both co-op and solo and provides a myriad of environments. Love the easter egg song too. The boss zombies aren't obnoxious like on some maps and the huge amount of traps just tops it all off. Shrink ray FTW
6. Shi No Numa: Not much to say about this map. While it did do a lot to shape what zombies is today, it's just not a very impressive map. The design is kinda sucky and the random perks are a bitch. Not a bad map, but not great either. Only fun on co-op.
7. COTD: Fog and George Romero. 'Nuff said.
8. Moon: The environment and idea are amazing. The design, return of nova zombies, the astronaut zombie, and the fact that most of the zombies don't come from windows kind of ruins it. I understand trying to make a difficult map, but for the life of me, I cannot find a good strategy. I like the easter egg song and story development. But the other things just ruin it for me.
9. Nacht Der Untoten: This map usually satisfies my nostalgic feelings, but older doesn't mean better. Gets very boring, very quickly.
10. No Man's Land: Get's the heart rate goin. Then I remember that other maps exist.
11. Five: No map is bad in my opinion. All zombies maps are fun. I just never found my love for this one.
12. Dead Ops: Bored before I even start.