Better than Dead Money and Honest Hearts by far.
If you like the word "Science" and the expression "Let's do some Science", you will probably like OWB. It takes the "Science" to a living scale. Talking appliances, brains Calvert-style (Point Lookout), energy weapons (the kind that doesn't shoot laser or plasma), colored stuff at night, you name it. There is also the "Mysterious Broadcast" radio that helps you get immersed.
Without spoiling the story, it involves doing work for the brains you meet in the beginning of the game. There are multiple endings, but you get all trophies in one playthough and all are related to the story.
The gameplay is the usual thing, but now you can have a new haircut or a facial surgery, as well as your own home in the Big Empty. Better than the Lucky 38, because when finishing OWB you'll be rewarded a "weapon" that fast-travels you to your home in Big MT. Appliances give you things such as ammo every now and then.
The enemies, however, can be a real pain in the ass. If you have the "Living Anatomy" perk, you'll see that lots of opponents have a DTs such as 8. RoboScorpions have 400+ HP and Nightstalkers have 500+, making them a real challenge, as they come in packs.
Old World Blues is a DLC you don't want to miss, and the 10$ are well worth it. By the way, with the latest patch, if you have all DLCs so far you can go past level 45, which is sort of strange, because:
30 - Main game
35 - DM
40 - HH
45 - OWB
50 - LR
So make sure you are full of ammo, caps, good guns, Stimpacks and your armors are at 100% condition, because the Big Empty is tough and will take more than 10 hours of your life.
The reason why this isn't a 10 is because of frame butcher outdoors (Bitter springs framerate style before patch) after playing many hours in a row.