Teemo is a really fast moving fast attacking character, making him an easy character for people who are new to the game to use. Also being only 1350 IP gives people to the opportunity to buy him fairly quickly compared to some of the higher priced characters like Elise or Ahri. Even though he is a cheap champion to buy, he does a lot of damage is a short amount of time if built like mine. My personal best with this build is 57/1/1 against bots. I would not try this out for pvp. I think this build would get ganked against others. But if some armor was added the setup may work for PVP.

Ignite- targets enemy units, dealing 70-410 true damage (depending on your champion level) over 5 seconds and reduces healing effects on the target for the duration.

Exhaust- targets champion, reducing their movement speed by 40%, attack damage dealt by 70%, and their ability and item damage dealt by 35% for 2.5 seconds.

Ignite helps take that last bit of health the champion may have or bring them down enough for you to finish the champion off. When used along with Exhaust, it is almost a sure kill. Also exhaust may be used in a point where you need to run away. It slows the enemy down just enough for you to get away.

Greater Mark of Insight- By having nine of these runes, it makes Teemo's Toxic Shot do more damage, therefore helping get more kills. With the runes and by leveling Toxic Shot up as quick as possible, you can easily take down champions.

Greater Seal of Resilience- With this build, Teemo has a high attack speed and sub par damage/ability power, but his armor is not the greatest. These runes help out just enough to be able to kill the champions as they come and to make a getaway if you need to.

Greater Glyph of Potency/Greater Quintessence of Potency- Teemo's attack speed combined with added ability power to Toxic Shot equals a deadly combination. Every time he attacks, the toxic shot does extra damage. If the champion happens to manage to get away, the toxic shot does poison damage, sometimes taking the rest of their health if they are low. Also you may cast Move Quick, allowing you to catch and finish the champion off.

Pros

Fast Attack Speed
Fast Movement Speed
Can be used in any lane

Cons

Low armor
Tends to take others kills
Takes a few levels to get going

Overall this is an all-around build. Once leveled a few times, Teemo can jungle, farm minions, and take down champions with precision and speed. The Ionic Spark is an amazing item that helps farm minions while attacking champions. After every fourth attack, it sets off a chain lightning reaction, usually taking down a few minions or taking them to the point where they are one hit away from death. At the beginning, i recommend taking it cautiously because of the lack of armor. I also recommend getting the toxic shot maxed out as quick as possible to help with killing champions. Teemo's first spell is also good to use with Ignite and Exhaust. Getting one movement speed will help you catch the champions but i do not think it is a necessary to get until near the end. I tend not to use Teemo's ult, because even though the mushrooms do help a bit, i would rather have the poison damage from Toxic Shot and Blinding Dart.

If you have any suggestions about how i can make my build better or how your build compares to mine, please leave a comment.