Fallout 3

[Dark Ultima]

I have it, played and finished through the first 3 DLCs but have yet to buy the fourth.

I really enjoyed Fallout 3 the first few times. After that, I started downloading mods for it and the DLC from Games for Windows Live (and promptly fixing Microsofts mistakes and getting the DLC to work on my machine).

I have a heap of mods, about 1/3 I have made myself (either in the GECK or by tweaking previous mods) which I think make the game more enjoyable. I make enemies tougher, level ups further between, armor more noticably effective, skill points more linear (so even the dumb characters can get good skills, and so smart-asses don't max the skills before level 20), Perks don't rely on level (instead they have different requirements. Or are simply disabled.). Then I have other stuff like new hair packs, my own little hideout in Springvale, improvements to the environment, a sweet selection of sunglasses, various fixes for silly things that Bethesda appears to have forgotten, extra clothing, body replacers for male and female characters, replaced animations, improved decals, and replaced ingame posters.

Spoiler

Power armor training is available late game in Vanilla, after Project Purity. If you have Operation Anchorage, you receive Power Armor Training upon completion of the simulation.