I just randomly found a nice seed that spawns you next to an NPC-Village with all biomes (except Mushroom) in a close range. Heres a pic of the Spawn area on Amidst:
As you see there is also a stronghold near the spawn, and the seed also features a HUGE cave system with several intersecting ravines!
Here are the pics:
NPC Village and Stronghold
The Cave System
UPDATED WITH MORE SCREENS!
More cool stuff
Another Update - A huge Crater and DIAMONDS!
Nether Fortress and another huge cave system