Not much to celebrate for me as I first played it a couple of years ago. One of my favorites, for sure. I'd go as far as putting it on par with Fallout 2.
As far as mods go, I can't remember any specific names, but the biggest difference for me was adding darker nights and improving the enemy AI--there are different mods that do this, so you should do your own testing, anyway. The greatest thing about the game, for me, was survival and anything that enhances that part of the game made me appreciate it even more. This includes playing it Iron Man (I never got close to finishing it this way, always died miserably in some cave, but there were some really memorable moments).
The greatest fault from a world building perspective was the underdeveloped Legion. Not being able to explore the other side of the river, or having more complex interactions with the faction before Mr House were big disappointments. As far as gameplay, real time and VATS were kind of inconsistent. Rather than being alternative modes, you use each to exploit the game in different ways: sniping enemies from afar in realtime and switching to VATS for that close-range headshot. All in all, I prefer playing with VATS rather than without it, as it gives more weight to my character's skills rather than my own. Furthermore, I like taking my time getting in position to ambush the enemy, planting my first shot manually, etc., but I'm not a FPS player. Both systems could be integrated better, but I was still glad I could switch between both.
