This game is fun as shit. Probably my top game of the year, so far, perhaps tied with The Force Unleashed. I already have ten hours logged and I only got the game a few days ago which is EXTREMELY rare for me. Unlike most RPGs, which feel tedious, Fallout 3 is very engrossing. It's also deep without being cumbersome... Mass Effect had a similar level of good presentation and even a somewhat similar combat system, but was weaker across the board than F3.
Thus far, my character is basically an all-arounder. I have high Science and Medicine skills, with Energy and Small weapons being my items of choice. I have a big inventory of guns, a house in Megaton, and about 1,100 bottlecaps to my name. At level 7, I'm able to waste Super Mutants with decreasing difficulty (thank you Hunting Rifle & Combat Shotgun!) but I've definitely died a lot.
I don't regret getting the 360 version - no install times, no need to worry about HD space being taken up, very smooth FPS throughout (basically no slowdowns ever.) Graphics look great to me. My only gripe is that aiming is more annoying, which means I use VATS most of the time and do a lot more strategic retreating. Trying to pick up specific items from a big rack is also a little challenging, whereas with PC I could sweep the whole screen a little more easily. I think the game would be improved for console if they made the cursor a little sticky/magnetic when it came to moving over clickable/attackable items/characters.