I have a moderate sized collection of the Dwarven Forge fantasy sets. However compared to some collectors my set is tiny. Considering the cost (which just jumped up another 20% Monday), I cannot imagine where the money comes from. I often wince thinking about what I have spent (including the stuff I ordered last week before the price increase) compared to how infrequently I get to use it.
Be sure to check their forums and look at the pics of the setups some of their more dedicated collectors have been able to put together. There are some truely amazing setups.
I occasionally get to really cut loose with it and create some nifty scenery. I don't have enough to do my mind's eye full justice so I tend to take a different approach by using the DF stuff in combination with other materials to create a sort of scaffolding for myself and players to hang our own mental tapestries on.
Here are some pictures a friend of mine took of some Dwarven Forge setups at a game day event.
Otherworld Miniatures. Well, there would be if I ever get around to painting it. It comes with assorted tiny fake gems for the eyes in different colors. I think I will stick with the classic ruby scheme, though I might leave the right one out to sort of hint that the folks from the AD&D 1st edition cover got there first.
In case you are wondering about the flames on the bridge, those are from Galeforce9. They make a bunch of different odds and ends that can be useful. Among the stuff I have from them of course is flames, smoke, ice, etc.
Sandra Garrity who has sculpted a lot of miniatures for Reaper has taken on the task of sculpting the next big release for Dwarven Forge. It will be an "outdoor" sort of set that the previews on their site make look pretty interesting. I could easily see something like it being stumbled into deep in a dungeon by bewildered adventurers.