How do you say your Russian is good in Russian?

Depending on whether you want to sound formal or informal, it would be either:
"Вы хорошо говорите по-русски"-- "Vyh khah-rah-SHOH gah-vah-RIH-tye pah-ROOS-kih" or "Ты хорошо говоришь по-русски"-- Tyh khah-rah-SHOH gah-vah-RISH pah-ROOS-ki"