I started playing FO3 last night and have been doing some of the Megaton area quests. The intro sequence with you growing up was quite creative and well done. The open-ended feel of the game is great, and the story and atmosphere have been quite immersive so far. On the other hand, I don't like the random, chance-based gameplay mechanics present in a lot of things. I don't know if this is common in RPGs or what, but it's annoying. The actual combat has been pretty easy, and VATS often makes things even easier.
The game is definitely full of bugs. I already had three or four crashes, one of which required a reboot since it kept stealing the focus. The NPCs behave oddly, frequently bumping into and pushing each other around, and talking over each other constantly. There was also a huge bug where you couldn't get out of the pip-boy if you remapped the key for it, although this was fixed in the most recent patch.
Also, this game has a Doom 3-esque microstuttering graphics engine that is intolerable at anything below 60fps. There is a config file option to fix it, which is pretty much essential. It messes up the lipsyncing and you have to keep the framerate above 30 or the game speed changes, but it's much better than the alternative.
Is there any place where can you sell stuff, by the way? I picked up anything that seemed to have a good value/weight ratio, so I'm carrying a fair amount of stuff now.