It's a bit early to call it a cult classic imo, but I'm still
surprised by the love for dead money based on how bad it was.
I know it's not actually a cult classic, just couldn't think of the appropriate word and that was the closest to my point. Personally, I voted for Dead Money; sure OWB has more humor but DM is just... tragic. The setting, the characters, enemies, the ending. Even if you do everything right, it still seems sad.
The Villa and the Sierra Madre are desolate places that you could once tell were beautiful (If, in the Villa's case, cheaply made). Everyone who lived there and survived are Eldritch zombies trapped in a cycle of emulation; going about their lives until something different wanders in and disturbs their little world, in which case they lash out and apparently drag them off in the Cloud.
And the Cloud itself! Hoo, sure it was a nuisance but in my opinion, which I respect, it wasn't made to be an actual threat. It was made as flavoring. It adds to the tragedy and atmosphere of the Madre--it does for Dead Money what the Survivalist did for Honest Heart. Imagine if these elements weren't added? Imagine the Madre as just... some ruin in the wasteland with an impenetrable Casino and weird unkillable Ghouls. Personally, I don't think it would have been nearly as interesting if the Cloud wasn't there. Just like how Honest Hearts would lose something if the Survivalist and his Camps were removed from Zion.
I've never understood why people seemed to hate Dead Money so much. It was made to be a story driven DLC and, in that regard, it did very well. The characters were all memorable, the villain was delightfully hate able, and the Madre had a powerful backstory to it. The only issues--ALA the Traps, Cloud, and Radios--could be annoying, yes, but with the exception of a few hard to find radios they were all easily manageable. I didn't even need a Stealthy character to get through.
I know that my experiences aren't the same as others, and quite a few people have had problems dealing with the dangers of the Madre, but if they weren't added to the game, could you honestly believe that the Madre was as dangerous as it keeps telling you it is? I for one would have left the DLC feeling disappointed at how easy it all would have been without them.
Each and every 'nuisance' added to the DLC added to the overall plot and atmosphere Obsidian wanted us to experience. The Madre was indeed a perilous place that, quite frankly, most would be wise to avoid. That's why Dead Money is, for me, the best DLC for New Vegas. It wants to tell a story, and it doesn't cut any corners while doing so.