Lol Yi? Really? He'd just pop- silence breaks Meditate so he can't just Stupid Mres it.
Morde, Morg, Kass, Galio are the best options.
Malzahar shouldn't do too badly as long as he's sufficiently good at predicting blinks and can facelaser her before she can get the silencing cast off. Otherwise, he'll still push harder than she could ever hope to keep up with, meaning if he doesn't feed her, she's not getting fed. Or mid's losing two plus towers by 20 minutes. That'd work too.
As to people she *doesn't* truly counter, it's a true match of skill if you throw an Ahri against her. LB's biggest advantage against Ahri is that she's best set to start the duel on her terms. However, it's also her biggest disadvantage- a properly predicted and countered Distortion will completely destroy her, and Ahri is in the right mentality to do that post-six.
Technically the same with Kass, but his passive gives her a really hard time- free 15% resist she can't negate is pretty anti-burst XD