I got tired of rebuilding the same thing everytime I started a new world. So I made a Underground base that I could reuse with Worldedit/McEdit and save myself a couple hours.

I made it larger than I normally do so that it can accomadate more people.

It has a Tree, Wheat and Sugar Cane farm area, 6 beds, Furnace wall, Chests, Nether Portal Room and more importantly for me an automatic cart loader.

Link to more images

Additional Notes

The cart loader needs to be 'freed', there are blocks blocking the top of the loader. Makes you go and have a look.