Silver-Tongued Devil

This is a Fallout 3 Xbox 360 Achievement. You earn this by winning 50 Speech challenges.

Easy Gaining
If you go to Big Town, speak to "Bittercup", who usually is sleeping in the Common House. Talk to her until she speaks about her dating "Pappy" until she broke up and went to Flash. Once she admits she dated Pappy, exit out of the conversation, and go talk to Pappy. Then, 3rd option should be a Speech option that you can choose as many times as you want. Which, if you raise your speech skill big enough, you can make it a 100%, which means infinite Speech successes, which gets you this achievement really easy, plus infinite EXP.

I got over 2000 Speech successes and 12 levels in less than one hour!

WARNING: Try to do this trick before the Big Trouble in Big Town quest, because if you need to go back, there is a big chance that they all might be dead.