I have been playing Ezreal for some time now and i have seen alot of builds for him, ranging from ap ezreal to pure ad. After giving him several tries, i finally found a build that suits me(at least for now) and i would like to share it with the community.
This build focuses on AD ezreal, getting to land his mystic shots early game for alot of damage and late game as a way to deal damage but mainly charging up his passive.

So let's look at Ezreal's weak and strong spots.

THE GOOD STUFF
-Has a great early game;
-His E works like a damaging flash;
-His R gets those bastards who run away with 50hp;
-Passive becomes very useful in 1v1;
-His Q applies on-hit effects, which combined with its' huge range will annoy the **** out of your opponents;
-Very low cooldowns, that is if you spam his Q;
-And more but i don't remember them right now :/.

THE BAD STUFF
-He is squishy, as hell;
-Hitting with his skills can become hard if you're not a great "skillshooter";
-His damage late game is not as good as his early game damage, tho this doesnt mean the damage is bad;
-Sometimes killing the 50hp runaway squishies with R can be hard because sometimes people take the oddest paths;
-Very mana dependant;
-No CC(except for attack speed reduction, which i dont really consider a big CC);
-Takes time to master;
-He's a bit....girly :|.

So, in a nutshell, Ezreal is a glass cannon, with a good escape mechanism, which, if played right, can carry the team to victory.

- Rising Spell Force(Passive)
Hitting a target with Ezreal's abilities increase his attack speed by 10% for 6 seconds, stacking up to 5 times.
-This ability is what keeps Ezreal's damage late game, it will save you item slots for items with damage and survivability. So yeah, great passive.

- Mystic Shot(Q)
Ezreal fires a bolt of energy dealing 35/55/75/95/115(+1 per Attack Damage AND +0.2 per Ability Power)as physical damage(applies on-hit effects). Ezreal's cooldowns are reduced by 1 second if Mystic Shot hits a target.
-This is that thing that Ezreal does, it has a huge range, and the damage is good, specially early game, it kinda dissipates through mid/late game so its' main role will be to charge your passive, while dealing some damage aswell.

- Essence Flux(W)
Ezreal fires a wave of energy that damage all champions it passes through for 80/130/180/230/280(+70% Ability Power). Affected ally and enemy champions have their attack speed respectedly hasted or slowed by 20/25/30/35/40% for 5 seconds.
-This skill=meh, it's good for AP Ezreal but for AD, no big deal, the good thing is that it reduces/raises ur enemies/allies's att speed, good when fighting an AS dependant champ like Xin Zhao and whatever, but besides that its ****py.

- Arcane Shift(E)
Ezreal teleports to a target nearby location and fires a homing arrow at the nearest enemy unit dealing 75/125/175/225/275(+75% Ability Power) magic damage.
-This skill is pretty good, it's like a free Flash which also deals a bit of damage, you can use it to position yourself in teamfights, run away, chase, monkey around when 1v1,etc. it is a great spell, the damage itself is like Essence flux,it's not gona be ur main source of damage but it helps, u can also use this to charge ur passive like the 2 other skills.

- Trueshot Barrage(R)
This skill is what makes Ezreal famous(or at least known), it deals a ton of damage and it has a global range.It's just awesome, you can use it to catch those running luckers and in teamfights, its a huge boost. It will also surprise people when you 1v1, you just need to hit them, even tho its hard when there's only 1 person, easily dodgeable.

You should first max Mystic Shot as it will be your main source of damage early game, giving 1 point to Arcane shift for an escape maxing this one after you Max Mystic Shot. The last skill you max is Essence Flux, you should put a point in it just for some extra damage and for the attack speed component.

Greater Mark of Desolation Greater Quintessence of Desolation

I use ArP Marks and Quints for the sake of damage, they'l boost your damage through the game, CDR Glyphs, i think Ez needs CDR so that he can make his skills more spammable, specially E and his ult; last but not least Armour Seals, these will give some surviveability to Ez and are great help when you lane against AD Carries like or .

I will update this soon with other possible choices, i just dont have money yet for the whole rune collection so i cant try them all out yet. Feel free to suggest runes.

I use 21/0/9 for Damage boosts in Offense tree and for and Utiliy Mastery. I dont put anything in the Defense tree just because i prefer the bonuses the utility tree gives.

An "Each-Mastery-Explanation" will be comming soon, as im just too lazy to write all that stuff right now :).

and are the Spells i use.

-This spell will make you almost uncatcheable, with E and Banshee Veil save it for the big stun, dont waste it on situations you know u can get away if u don't use it, only use it when you're in the Sh*t.

-I just love this spell, used for chasing, fleeing, and its a beast against AD's, just slap this in their face and melt them with all you have.

~Other Options~
Before i thought of Cleanse i used this and exhaust, its a good spell to shut down regen dependant champions like and Lifesteal Champs like . Otherwise i just prefer cleanse because of the extra surviveability.

I dunno, i see alot of Ezreals with this one, i just don't give much use to it when i use it, i usually only need my E to get away, all you need to do is know when to use your E and how and you won't need flash.

I haven't tried this one yet but i think it's the same reason as i dont use Flash, i gota give it a try once tho.

Here's the big thing, ITEMS.

You should always start with this item, it's self explanatory.

The 15% CDR they offer will stack with the CDR from ur Runes and Masteries giving a total of around 23%CDR which is very useful for your E and R, (specially R you'l be spamming this one every minute)

I really suggest getting a manamune instead of clarity runes, you should get this as it will not only fix the mana problem, like it will give you alot of AD from all of the mana you get from Banshee Veil and , giving you a total of around 90AD(according to the mana they show here i still have to do the real thing)

It'l make your Q hit harder as it procs with it.

This item will help you you faming and the ward is always helpful, besides the lifesteal will keep you up untill late game, where we will sell this to get another item.(still thinking if this item is really worth it, update here coming soon)

Awesome item, protects you from those Enchanted Crystal Ice Arrow and Curse of the Sad Mummy, helps building AD with , and with your cleanse, catching you will be hard.

With your farming this item becomes very powerfull, the Lifesteal, the Damage, really great for Ez.

Upgrade from Sheen,will give you more movement speed, the Phage effect and a stronger Sheen

You should sell Wriggle's Lantern and buy this item IF the enemies are filled with HP,Bloodrazor will shurely solve the problem.~

Get this instead of Madred's Bloodrazor if the enemies are filled with Armour.

Coming soon..

Concluding, Ezreal is the skill-shot guy and in the right hands he's a beast.He's quite underrated aswell :/
Leave suggestions in the comments, more tips through the game and etc will come soon, when i have patience to write.