Is there any micro-controller with ADC > 20 MSPS?
As said by pjc50, typical maximum is around 1 MSPS. But there is some MCU that goes a little higher :


STM32F302 series : 2 ADC with max 5.14 MSPS @ 12 bits (each) / 9 MSPS @ 6 bits. And it seems to have an interleave mode between the two ADC to have higher MSPS.
http://www.st.com/web/en/catalog/mmc/FM141/FM141/SC1169/SS1576/LN1824/PF253739
NXP LPC4370 goes up to 80 MSPS @ 12 bits : http://www.nxp.com/products/microcontrollers/cortex_m4/LPC4370FET100.html


It seems that NXP had some high speed ADC so check out NXP site to find others MCU. Also check the datasheets, I'm more digital than analog EE.