What are some good seeds?

You will have a hard time finding caves that enter from the top of a mountain, but there are several seeds that do have surface caverns and caverns that start at the bottom of a mountain.

For a great cavern with some good flat land, try seed "404" This will spawn you on a gravel pit which you can punch and will cave in to a large cavern.

Add me if you want my GT-xColaDudex I have a place with like 20 tunnels

Gargamel gives you a large mountain range.
Asdf apparently has some caves with diamonds in it.
Theworstseedever has a dungeon on the surface with a large cave in it holding a bit more than 21 diamond!

For a cool seed put in -77+1001 you spawn in front of a fountain and if you look around theres alot of cliffs and stuff. My GT is I360 SNiiPeRz

Hey i know a lot of good seeds including some of my own. My GT is knucklebumpp557 if you want to add me

I found two seeds called mobmod and creeper peeper i tested both and every time I spawned in a world with flatlands almost everywhere.

One seed is 404. Another one is 888, for a flat land.

Another one is worstseedever.

The best seed I have ever found (for any purpose) is 1337. It has every type of block somewhere on the map. There is snow, desert, forest, flat plains, mountains, and lakes. There are pumpkins, sugar cane, cacti, and mushrooms. I find wolves all the time (I currently have 7). There is lava on the surface in at least 3 spots. There is a very large tunnel system where I mined about 5 stacks of iron, 6 stacks of coal, 9 stacks of redstone, almost 3 stacks of gold, and about 45 diamonds. That's all from one cave system! There are at least 3 other large cave systems, and a lot of the iron, gold, and diamonds weren't even buried. A great multiplayer map.

Ok for any of your minecraft hunger games needs add me, abayle01 (Xbox live) and I have a match every Friday night at 7:00 pm central standard time right now I have fifteen spots filled and have nine more open. Join soon and I will give you diamond armor! Actually let me rephrase that the first 5 to join next get all diamond armor and swords. So just add me (Xbox live only) at abayle01 not trying to get more friends just got some spots to fill to make it a good match so just join!!

These are some good seed names:
WORSTSEEDEVER
BESTSEEDEVER
ASSASSIAN

For the most recent update ive got an awesome seed. It has no mushroom island sadly. But there are a few redeeming features. It has some mountains, large forests both with and without snow. Most of the southern portion of the map is snowy plains and has many natural caves, a small desert area with i believe just one village. Also located at "X:118 Z: 159" is a large hole in the ground that is the perfect shape and depth for building a multi-layered home aka house with a basement or just for mining. The area near the hole has a few trees that can be cleared out to make a wonderful view of the water near by. But by far the best feature is there's a strong hold located at the bottom of a ravine. The coordinates for the entrance of the ravine are "X: 14 Z: -76" The seed is "15". Seriously just the number "15". ENJOY!!

try shooznot beary diamonds.It has mines, caves, and ravines.

(TE9CH IS BEAST)- Its good for everything.

If any questions about the seed (TE9CH IS BEAST) Just add SW4GG M0N3Y and send me a message saying that you need help on it.

You people are using the most original seeds there ever was. Why can't people find their own seeds and post them. Every one has seen the ones your posting but if you put in your own seed it might make people actually look. "JOO4YOU" is a good seed and im still looking around for what it has and what supplies I can find and within 5 mins. I have found 23 diamond 5 stacks of iron 2 stacks of gold and over a full chest of coal. The biomes are amazing and it has a lot of good building spots.

Well if you're on XBOX, you can message me gamertag Tamaerus (please no friend requests, just messages) and tell me what you're looking for; I'll check my seeds or make new ones to see if I can get something workable for your needs. I'm not exactly sure what you mean by "crazy mountains" because everyone has their own opinion on what that constitutes, which is why I'm not actually posting any seed numbers right now... :) Anyways, feel free to ask, and if or when I get your message I'll be sure to test out some numbers and words for you. PS- I rarely visit forums more than once or twice every couple weeks or month, so XBLA messaging is best.