Simple question - I went a little nuts modding FNV, and I want to remove them and start over. Being an idiot, I forgot to keep track of what mods I'd installed. Is there a master list somewhere of the files I shouldn't be deleting, or would it be quickest just to kick out everything but save files and redownload the thing?

if you have to ask, redownload the thing.

Next time use fomm and package manager. In most cases this would have saved you. All you would have to do is select the mod from the menu and click, it'd hunt down everything that mod added.

Uh... If you take a look at the FNV Launcher you'll see there's an option called Data Files. You could uncheck everything in there except FalloutNV.esm, which will disable the mods you're running. For texture and model replacers, it's a little more tricky. Deleting the folders Data\Meshes and Data\Textures will remove all custom made graphics content. If there's a file in the game folder called ArchiveInvalidation.txt delete that one too. Don't delete Data\Sound, Backup, Music, Shaders or Video.

Yeah texture/mesh issue is what my advice was mainly for. Although, I have an odd issue even using package manager, I had a replacer for various things, roads/faces etc. I uninstalled it and got pink faces. Really odd thing was I had Archive invalidation on. I even turned it on off again to no avail.