I like them all well enough, with caveats.
OWB: Overall the better of the three in my opinion. Funny, entertaining and very enjoyable. Lacks a bit in the visual appeal. Roboscorpions have a crap color scheme.
HH: Very pretty, lame story, great sub-plot with the survivalist. Good weapons, lot's of harvestable plants, but no Pinto Beans http://www.youtube.com/watch?v=4Z2Z23SAFVA Why, oh why are Pinto Beans as rare as chicken teeth? Explain to me, EXPLAIN TO ME!!
DM: Best Atmosphere, great visuals, story is interesting and Ghostpeople rock, but I though the implementation was lacking. Gameplay, once you learn what to look and listen for, is just tedious and way too easy. The only time I actually died was
Spoiler at the end, trying to escape from the vault before my collar blew (I ended up sneaking out)
.