Downloads mods from Oblivion Nexus and installs them for you and it's perfectly safe and very easy to use. Also supports games like Skyrim, Morrowind and Fallout 3.
Kind of slow and glitchy, but it's due to how it's still in beta (after three years) and how the Nexus servers are always having problems.
9/10
According to a lot of people, Mod Organizer is much better, but, to be honest, NMM does everything I need it to and it does it well enough, so I never really found the need for MO.
Automatically sorts out your load order on startup and provides useful information about your current plugins, such as missing .ESMs, side notes, incompatibilities, what should be cleaned etc. Also works with Skyrim and Fallout 3.
Allows you to clean mods for better compatibility and plenty of other features.
10/10
It is pretty much mandatory for everyone who will ever use this to watch the tutorials. Gopher made a really good tutorial over here for TES5Edit, but most of this applies to TES4Edit too, since they are essentialy the same thing, just for two slightly different games.
Most people experience annoying errors when quitting Oblivion. This not only prevents that, it saves the changes you made in the video settings or controls into the .ini when you quit, so you no longer have to reset your settings when you restart the game.
Oblivion's default low console FOV can give headaches and nausea, and that was the exact problem for me. Before I discovered this mod, I always had to open the console to change my FOV, and that was incredibly annoying. This mod just changes your FOV to 90, and that's pretty much it. You can also set a custom FOV.
Makes changes to the water to make it more realistic and aesthetically pleasing. For example, making water more foggy, enhancing ripples, etc. Completely overhauls how the game renders water.