Acronym for Thanks For The Memories, rapidly becoming an internet colloquialism. It's generally appended to a winning remark to enhance a user's satisfaction upon victory over a situation.
The phrase is also a play on the Fall Out Boy single "Thnks Fr Th Mmrs".
AkiraBoss: you only won cause i have a noob team and bad lag
AkiraBoss: wanna 1v1 and i'll show you who's noob?
modestdude: gg tftm
JellyBurger: i'm not a feeder if my score is 3-12
AnyoneWithABrain: rofl gg tftm
Acronym for Too Fat To Masturbate, a horrifying condition in which a person is too fat and disgusting to get themselves off.
When you have to dip yourself in flour first, you're TFTM