Overview

When most people think of Alistar, they think of a tank with some elements of a support champion. While he does excel at this role, people don't usually evaluate his other good qualities, and I have yet to see a build designed to make Alistar a force to be reckoned with in terms of damage output instead of simply a tank that can knock people around.

While this build does maintain some of Alistar's tankiness, it also seeks to improve his other traits which are so often overlooked.

Alistar is a viable addition to any team. His combination of toughness, support, and ridiculous cc (he's got very few peers in the cc department) makes him invaluable in any team fight, and this build is designed to make him as well-rounded and utilitarian a champion as he can be. The idea is to use Alistar's ult to keep him alive with little health. If you are successful in doing so, Alistar will be incredibly hard to kill, extremely disruptive (due to his Q and W) to the enemy team, and able to dish out some seriously rough blows to the enemy.

This build has a lot of versatility. Alistar can fill a lot of roles if played correctly, and this guide is meant to use that versatility to its fullest.

Items

Many people will disagree with the decision to use Boots of Swiftness instead of Mercury Treads or Ninja Tabi, but speed is extremely important for chasing, running away, and getting where you need to be when it counts (a trait that is commonly disregarded is unimportant). Alistar is a slow champion and this can be difficult to deal with. If you don't play your cards right, you will see your enemies fleeing while you chase fruitlessly. You will see the enemy slowly, tortuously gaining on you as you run for your life and eventually are chased down and killed without mercy. OR you can follow the build, stop enemies dead in their tracks, and make miraculous escapes from deep within hostile territory while the other team is left in the dust. It's your choice.

If you want to do damage enough to make a difference in team fights, you're going to need to play Alistar a bit offensively, which is something that most people aren't used to. Trust me, if you can get the hang of this build, you will win game after game as your opponents are frustrated by how meaningless their efforts have been. Alistar suffers from fairly low attack speed, which is why I chose to include Ionic Spark. This item and Trinity Force will allow you to dish out some heavy blows when used in combination with the passives from the Maw of Malimortius and Trinity Force (especially when Alistar is at low health).

Guardian Angel's passive will allow you to sustain a state of low health, thereby elongating the time in which Alistar is useful in a fight. By the end of the build Alistar should have enough health, armor, and magic resistance from his various items to keep him going for an extended period of time.

Masteries

These masteries focus primarily on bettering Alistar's early game, simply because he is generally ineffectual in lane at the start of the game unless he is with another strong early game champion. Ranged carry's generally fit this bill, as do champions with leap, charge, or teleport abilities (such as Jax, Yi, or Talon, respectively).

Mana regeneration ensures that you won't need to go back to the summoner pad too early. Alistar can stay in lane basically forever if he has enough mana regen due to his heal skill as long as the player doesn't make stupid decisions and expose himself to damage unnecessarily.

Attack speed and damage provide that extra boost that can come in so handy when it comes down to the wire when it's just you and your lane mate against the other guys early in the game. Armor penetration helps to insure that you will hit your opponents hard no matter how tough they are.

This build, while it makes Alistar very hard to kill or even to deter, is not for pure tanking. The extra bit of early health and health regeneration helps Alistar to be more intimidating to his opponents (keeping them on the run from you is key because it gets inside their head, and more importantly it keeps them from putting down too much harass), and keeps him from succumbing to harass too easily. This is very important, as it is hard to deal with a ranged opponent if you can't get close to them, which will most likely be what happens if you face a strong ranged champion in the early game.

Runes

I can't emphasize enough the importance of mobility to an Alistar player. If you can catch your enemy, you can pretty much put them wherever you want using your Q and W. If you are with your teammates, this will pretty much ensure a kill or assist every time.

The mana regeneration glyphs keep Alistar sustainable in the early game. The armor helps with early game harass from ranged AD characters.

These marks (runes which you rarely see in use) keep him a formidable opponent against most champions during any part of the game.

Skills

The skill choice sequence is designed for 2 things.
1. Survivability. Alistar's heal is a great tool for quickly getting some health back during a fight, as well as despensing some easy HP to your surrounding teammates. It's extremely effective during pushes, as it can be used to keep minion waves at full health until they crash into the turret like a cannonball.
2. Shorter cooldowns. Alistar's heal also has the quickest cooldown of any of his skills. In fact, it's incredibly quick when there are minions dying around you. It's possible to use this in combination with Sheen/Trinity Force to add a very substantial amount of damage.

The Q and W are fantastic skills, obviously, but their primary purpose is for manipulating the other team, not dealing damage. They only need one or two points early in order to do their job effectively.

Conclusion
Well, that concludes this build. It's the first that I've written, so pardon me if it isn't very flashy. I think you will find it highly effective, however, if you can manage to look past the lack of flair.

Anyways, enjoy!