Cho'Gath is generally played as a tank. This build takes his tanking to the extreme, offering the ability to absorb incredible amounts of punishment, while still retaining the ability to be a threat.

The runes are mainly defensive, with a balance between bonus armor and magic resist. The marks offer early magic resistance to counter mages who can spam early, such as Karthus or Kennen. The Glyphs provide additional mana which is vital for Cho to stay in the field.

Starting off early with the regeneration pendant is good for Cho. With it and his passive, he can stay out for quite a bit of time early on. When building Force of Nature, be sure to build the Negatron Cloak first. It will allow him even greater protection from mages. If the enemy is incredibly AD based, you can go for the Thornmail first, but only if they have 3 AD champions, or two AD champions in your lane. Alternate items for the later builds includes Randuin's Omen for Zhonya's Hourglass. If your team lacks magic damage, this will boost your ability power, while still providing armor. Frozen heart is also an acceptable replacement for Thornmail, if you find you are running out of mana early. Many people decide to build Warmog's with Cho, but I find this to be redundant. He already achieves large ammounts of health, and I would rather have additional armor or magic resist. After all, that one DPS champ with a Madred's will end your day pretty quickly without good magic resistance.

Rupture is an obvious first choice. It deals good damage, pops 'em in the air and slows them. Good for chasing or slowing them from getting you or a teammate. Feral Scream is also an excellent choice, because you can silence multiple targets at once. I usually skip on Vorpal Spikes until the very end, because I would rather have high power slows and silences than a little extra damage per attack. Obviously, take Feast as soon as possible. Feast as often as you can until 6 stacks, then save it to take down unwary champions who are wounded. Since it deals true damage, opponents often underestimate its power. Rupture and Feral Scream are also good for harassing, should you have good mana regen.

Teleport is essential, as it allows you to get to teamfights quickly. As a tank, you should always be in the thickest action. Most people prefer ghost, but I prefer Flash because you can jump through terrain and have an easy get away. Acceptable alternatives include Clarity for mana support.

Pros:
-Exceptional ability to absorb damage.
-Good support for AP champions.
-Good against AD champions.
Cons:
-You might get ignored sometimes.
-Weak against other tanks
-A bit of a slow response time.

This build offers a unique aspect of Cho that people don't seem to notice as much. They see his bonus health from feast and decide "He needs even more!". I have seen quite a few Cho's who try and build incredible amounts of hit points, only to be taken down because their armor or magic resistance was terrible. He doesn't need any more health people! With full stacks from Feast, along with Banshee's Veil, he is one of the beefiest tanks out there, all without having to devote item slots to redundant health items. Many would argue for the Atma's impaler and Warmog's combination, but all of his abilities scale on AP, and have decent bonuses at that. The 'negligible' 170 ability power provides a 1:1 ratio for Rupture, as well as 120 additional damage to Feast and Feral Scream. Additionally, the Abyssal Scepter (an unpopular item for reasons I cannot fathom) provides a buff that lowers enemy champion's magic resistance, thereby increasing your own, as well as any allied mage's damage.

Cho'Gath is best in the fight, ready to go. When a team fight is about to happen, pop your Rupture in front of you, and boldly charge in. Always be the first into the fight, so you can absorb as many spells as possible. Also try to position yourself in front of squishier champions to take any single target spells like Mundo's Cleaver. Right when you enter the fray,cast your Feral Scream to silence as many targets as possible. This should give your team a large advantage towards the beginning of the fight, as the silence from Feral Scream lasts for up to 3 seconds. Target their carries or squishy supports immediately, drawing their attention. When Rupture is ready, place it directly under their feet. If they don't see it, it will throw them in the air, making them much easier to kill. Keep Spamming Feral Scream as much as possible, and look for any wounded champions to finish off with Feast. It is easy to get overconfident with such incredible defenses, but be wary. If they have multiple stuns, or catch you all alone, it is very difficult to survive. If they focus on you in a team fight, well, you're just doing your job then.

Farming is one of the hardest and most important things to master in League. It's even more important with Cho'Gath, because of his dependence on defensive items and his passive. If you are low on health, don't hesitate to use an ability or two to farm some minions. This will restore some health, as well as refund a little bit of mana. If you are low on mana, but have lots of hit points, stay out and go for some last hits. If you are cautious, you can get your mana back, and thusly stay in the lane for an even longer period of time. It is possible to stay in the lane for up to 15 minutes without having to return for mana even when spamming abilities, as long as you are careful, and farm well.

This build allows you to be a primary tank. With the full set of items, you can tank almost anything. Turrets will deal next to no damage, as will support champions. Feel free to tank turrets, even if they have a champion near them. Just attack the champion to draw the aggro, and let your teammates take it or the champion down. It is important to note that Cho is a mana hungry beast, so don't go wasting abilities on minions. If your health or mana gets low, just remember if you can get some last hits, you'll regenerate some. This can keep you out in the field when others would have to go back, giving you an advantage in experience and money. In short, Cho'Gath is a superior tank and team fighter when played properly. As long as you don't get overconfident, you can lead your team to a win.