I have a gigabyte motherboard G41M-ES2L what cards can it support?

you can use any PCI-e x16 card(any generation,cause PCIe3.0 and PCIe2.0 are backwards compatible), the real question would be, do you have enough power from your PSU to support it ?
so you most check your PSU quality and power possibilities acording to the max TDP of the GPU you are planning to get.