Below are my detailed picks for the five "must have" graphics mods, and as to this date, the 5 best Fallout 3 graphical mods.
5. Fallout 3 Re-Animated - I'll be frank, sometimes the default Fallout 3 animations just look whacky. This mod, developed by a professional animator as a project of his spare time, aims to correct that. In the 80 animations this Fallout 3 mod includes, every one of them makes the game look tremendously more natural.
The original "idle aiming" animation from Fallout 3 is on the left and the altered version is ont eh right. Needless to say, one looks much more natural.
4. Fellout - This mod removes the "green" light effect apparent in almost every part of the environment in Fallout 3. It lets the actual environment shine through clearly and seem much, much more realistic than before. It also allows for the environment to display more contrast, which gives a better overall graphics experience.
Pictured on the left is Megaton without Fellout installed and on the right with Fellout installed.
3. Enhanced Weather - Rain not "rainy" enough? Fog not "foggy" enough? This mod attempts to make the weather in Fallout 3 looks realistic. For example, your field of vision's outer reaches become foggy in a heavy rainstorm and likewise with a snowstorm.
Not only does it make these graphical changes, it also makes weather progressive. Instead of weather abruptly stopping, it first becomes cloudy and grey, with some thunder roaring before the rain cuts loose.
As would be the case in a real case of hard rain, your character's field of vision becomes limited when the storm finally hits.
2. EVE (Energy Visuals Enhanced) - EVE adds a whole new level to energy visuals. You know that energy pistol you picked up during Moira's quest int he supermarket? Now you have a reason to have fun using it. If I were to make a simplified (and potentially dangerous analogy), EVE upgrades Fallout 3's default energy visuals like the upgrade in visual effects that the 2009 Star Trek film provided for the 1966 Star Trek series without the horrendous change in story.
Not only do the lines produced by energy weapons look better, a "misty glow" is added to hit objects making for an even more entertaining sight.
1. NMCs_Texture_Pack_for_FO3 - NMC, the author of this mod, took a year to remake Fallout 3's textures by hand. This is why by most, inclusive of myself, this is considered one of the best texture mods to date. The textures included in this pack are 400% the size of the original Fallout 3 textures. The difference is not only in the resolution of the textures, but in the details.
For example, many "effect" textures, such as tree damage, paint flakes from bricks, and even junk piles have been completely redone so that they are in fact more detailed and more interesting to look at.
Many textures, trees included, take on an entire new life of their own with NMC's Texture Pack.
That's it; the five best Fallout 3 graphics mods. Some mods require FOSE and a Fallout 3 memory boosting program (such as FO3 Ram Boost) to be installed to work properly. While having your settings on maximum with all of these mods installed and simultaneously activated requires a top-of-the-line PC, there are also some low-hi-res options available in to mods like NMC's texture packs for medium-end PCs.
In closing, I have but one thing to say: Fallout 3, with mods, can be equatable to Crysis a few years back in terms of being top-of-the-line graphics. Installing just graphics mods can make the entire Fallout 3 playthrough experience revived in terms of fun for anyone who has played every possible class and back-story combination!