All that stuff and more.
Now, how best to describe this amazing game so you will properly understand how great it is? Well, I guess just imagine you were actually in a post-apocalyptic wasteland trying to survive. The level progression in this game feels incredibly natural compared to most RPGs. You can travel anywhere you want right off the bat, but straying too far from the first town and sets of missions can become a deadly game of survival in which you'll likely not survive. This in itself can make exploration very fun and satisfying. Traveling the wastes of Washington DC is truly a unique experience. There will be many times as you gaze past a ruined highway and see destroyed office buildings and stored in the the distance, followed by the sillhouette of the ruined Washington Monument when you ironically will say to yourself "this is beautiful". This game nails the tone of a post apocalyptic world. It is a depressing, ironic place. You will walk through a ruined children's park and see the skeletons of the children who were playing there and feel a moment of sorrow that things have come to this. It won't last long as you're attacked by 2 deathclaws and barely make it out of the park alive. These moments are non-stop no matter what you're doing in this game. Missions are usually entertaining and often dangerous. You might be going into the supermutant filled inner city to find your father's last known whereabouts, all the while fighting for your life, or you might be helping the local shopkeeper research the surrounding countryside. There is so much to do and it's all pretty much done well. YOu will almost never be doing the same thing twice. In fact the game will trick you a few times into thinking you know how a mission will turn out from past experience only to have your world turned upside down. Times like these slong with the attitudes of the NPCs and propagamda strewn about the land lend a healthy doseage of dark humor throughout the game. This keeps things from being overly depressing, while never straying from the fact the the world is a ravaged husk of it's former self.
The add-ons are an area that could have used improvement. Often these extra areas are glitch laden dens of mediocrity. Anchorage for example has horrific AI issues from your enemies. They will often not even register you as a threat until you're shooting them in the face. Still, these 5 DLCs add to an amazing game. And you can't go wrong with more of a good thing. They all have extra missions, weapons, stories and areas to explore. And never take away from the core experience. Definitely worth picking up.
COmbat is the meat and potatoes of Fallout 3. Thanks to the unique VATS system each encounter in this messed up world is fun and exciting. Targeting specific body parts and systematically destroying them can give you a great sense of revenge on the a-hole raider shooting at you. Especially considering the awesome amount of gore the ensues from these blasts. Exploding an enemy's head can result in an amazing slow-motion display of skull-parts, eyeballs and blood.
All in all this is definitely one of my all-time favorite games ever. Future iterations may improve upon this awesome formula, but this game will always stand out as the first truly immersive post-apocalyptic FPS-RPGs. I can not recommend it enough.
P.S. I just have to add in, I finally made it to Broken Steel and have a few things to say. First off, the ending of the original game is both awesome and frustrating. It was a glitch-filled time of immense frustration that costs me an unnecessary hour or two of game time as I had to revert back to an older save file from several missions earlier due to a key character getting stuck on an environmental object. Once I started the last mission over however it did go smoothly. Luckily I am used to Bethesda's tendency for glitches and always try to keep a few save files for just such an occasion. The end battle is quite fun, and starting Broken Steel was a very pleasant endeavor. Although the game forces you to make a rather jerk-ish decision in order to continue playing. Seeing some of the fruits of your labor is an awesome feeling. You truly do feel like you've accomplished something special. Anyway, that's really all I had to add. Be careful of the endgame and make sure you have a backup save before you take on the final mission ("Take it Back").