So, this is my Lee Sin build that I use for laning. I like Lee Sin a lot, he is a great tanky dps with nice mobility. The build is meant to build a tanky damage dealer, and that's what I like. Also remember, this is my first published build ever, so it might not be "perfect". I appreciate feedback, especially CC. (constructive criticism)

Pros:
-Tanky
-Lots of damage through the whole game
-Nice mobility with the skills
-CC
-Fun to play with. This part is very important. This is only a game, remember that.
Cons:
-Uhm
-Err
-Yeh
-I dont know. Suggest me some o.o

My rune choices are pretty simple. Armor Penetration, Attack Damage, Armour, and Magic Resist. They bring you some durability trough the whole game. Your early laning is very strong, With Armor and Magic Resist combined to Doran's Shield is actually very effective. Other nice rune choices are more durability with Health per Level or Health Regeneration. Also you can switch The Quintessences to pure Attack Damage and make the Marks give Armor Penetration. You can play a lot with runes.

These masteries focus more to damage than durability. The 21-9 combo is pretty common, I'm not even sure do I have to explain it. Well anyways, Improved Ignite and well, improved damage on offense. And on Defense, there is Armor, Magic Resist and Health Regeneration for some more durability. Of course you can change the masteries to bring even more damage, or to focus being tankier.

The items are meant to get you durability earlygame, then focusing on damage, and then bringing some more durability.
A Doran's Shield at the beginning gives you durability. I wont be explaining this.
Then the Boots of Speed. All important. Not much to talk about these either.
Warmog's Armor. This is your first "real" item. It's a great tank item. Health, Health Regen.. It'r great.
Mercury's Treads. These are great boots, bringing durability against mages. Of course, if you are a lot more worried about enemy teams Physical Damage, you should consider Ninja Tabi. I personally like Mercury's Treads more.
Atma's Impaler. This brings some damage, finally. It also gives armor, overall a great item.
Frozen Mallet. Gives health, and slows enemies on hit. Great for a tanky melee.
The Bloodthirster. Lifesteal and Attack Damage. Enough said.
Randuin's Omen. Durability. Gotta love it.

Remember, these items are the ones I usually use. You can modify the build as much as you want. But main point is Attack Damage and Durability.

Some items and when you should buy them:

Dorans Blade. This could be a good starting item also, if you want to focus more on the damage.
Ninja Tabi. If the enemy AD is just killing/dangerously damaging you, you should consider these boots.
Banshee's veil. This brings some health and magic resist, but the mana is useless for Lee Sin. Also, it has a spell shield. It's cool.

A summary of the summoner spells while playing Lee Sin. (or what I think about them)

Flash: Yes, Oh god, yes. Escape, gank, chase.. Yes.
Ignite: Very nice. Damage+reduced heal. Good for finishing kills also.
Exhaust: Another great spell. Slow, reduced Attack.. Slow great for chasing, or using to AD carries while fighting. You can also exhaust your chaser to escape.
Ghost: Maybe, maybe. Speed is always useful. I don't personally like it.
Smite: If jungling, Yes. If laning, No.
Cleanse: Sometimes good, but not really ideal for Lee Sin I guess.
Heal: Hmmh, you can use it, but well.. Lets leave it to low level games?
Surge: Err. Well, if you want to....
CV, Clarity, Garrison, Revive etc: Don't play meanwhile drunk. You don't even consider these while sober and playing Lee Sin.

So, that was my Lee Sin build for Laning. I really appreciate all of the votes, and CC. (if you're asking now what is CC you didn't read the build. And I'm not talking about crowd control!) So, go play and have fun!