This seed is so good I have to share its awesomeness.
Seed: -2906800583407840952 (be sure to use the dash when adding it)
This seed has everything; beautiful caves, abandoned mineshafts, a Stronghold, almost all the biomes, a very useful river, dungeons, NPC village and lots of easy to access to resources.
The map is essentially several large islands that form a sort of bay around a medium sized ocean. Lots of land and plenty of water for boat navigation (which made early exploration really fun and easier to not get horribly lost)
Some features and coordinates:
The easiest to find is the one that is at the bottom at a very deep ravine X 43 Y 35 Z 200
The others are: X-206 Y 28 Z 26, X 177 Y 44 Z 228, X 204 Y 22 Z-319 sadly one of them is split by a ravine so it is all wonky, but still a blast to explore.
Some other features and shots of the seed
|Taiga during a snow|
|yes, there are slimes a plenty|
|lots of dungeons|
|a nice sized desert|
|FANTASTIC view from the extreme hills|