People , don t underestimate Alistar as top laner becuase Riot told you that he is a support.
Tank support champions like Blitz is a perfect exemple of a champion that is good as a solo laner.
Pesonally I think a support champion lose a lot of potencial just by being plaied on that role.
Simle fact that prove my point is Gold
Support is the role that don t have the "right" to steal Gold from the adc and should only get assists.
A Top Laner as the freedom of collect every gold possible and should get kills for what i like to call "Lane Lead" making every top laner way stronger then any support.
In this build you will find a AP Tank Alistar with way more power in Itens that as support would take half of a game to buy a finnished iten.

Classic top laner With Teleport and Flash

1ST Base Call - When having 760g or more buy a Sapphire Crystal and 2 Faerie Charm s, reason why, because Alsitar is a champion that consumes a really big percentage of his mana bar when ativating any ability, and other reason is that as a AP the base of your Damage is your abilities so you need to sostain your mana bar as long as you can or you will die. Buing this 3 itens means more tim in lane, more exp, more Gold and could give you the "Lane Lead"
Depending on how much Gold you collected (+760g) try to begin/had this 2 itens
Sheen/Glacial Shourd

2ND/3RD Base Call - In this part of your building it s up to the plaier and with thw Gold he earned to decide if A) completes the Iceburn Gauntlet with the iten missing (Sheen/Glacial Shourd) or if you complete the recipe on the 1st call ,750g for The Iceburn Gauntlet, and depending on the gold earned begin/had a Morellonomicon B) The Total opposite (+1700g)

Rest Of The Game - complete the boots in 1st place
Importante Itens - Warmog`s Armor and Fronzen Heart
Secundary Itens (Player decides) - Banner of Command, Guadian Angel and Zonyas´s Hourglass.

Start With HeadButt(W) for a safe early game.
With this Skill you can back away agressive Champions like Rivens, Garens, Jaxes and Sion for example.
wWhy did I mencion this champion? Well as you play againt any champion that I mencioned above have what I like to call "Predicteble Habilities". When a Rivens spins you push her and she is forced to finnish her stun in a minion, when a Garens Q you push him and cancel is Hability, Jax EQ combo is easily avoid by Headbutting(W) Jax betwin his E and Q the combo is failed, and Sion takes a long time to be used and you can easily block it.
Alistar Combos - W»Q - This is a good way to make your allies catch up low life enemies
For this combo you need to apply Alistar Q right after Headbutting(W) your enemy. If lucky you can your Q can get multiple enemies.
- Q»W - I recomend use this combo close to a ally turrent.
Get close to your enemy, apply your Q (it will make your enemy get "above air") gives you time to get on is back and HeadButt(W) him to the diretion of the tower making him take a few tower shots.
Passive: By using an ability Alistar gives extra damage to every nearby Creep,Monster or Champion. So make don t use you E just for healing but to make adventege of your passive.

Baiting : Alistar is great for baiting because of his Ultimate gives him way more armor and magic resist making you a great target for distraction.

The reason why i recommend go full health on Runes and 0/28/2 is because Alistar already give a good Magic Damage, Health and Tank Status is the only thing Alistat needs to suvive every fight.
The rest is all added with the itens bought.