Inf3rno82 :
Does my Gigabyte H55M-S2 support any of the new graphics cards (like with PCI-Express 3)?
Your motherboard has this spec:
1 x PCI Express x16 slot, running at x16 (The PCIEX16 slot conforms to PCI Express 2.0 standard.)
All new graphics card with PCI-Express 3.0 will work fine on your motherboard that has PCI-Express 2.0, as the PCI-Express 3.0 cards are backward compatible.
Also the performance difference between 3.0 vs 2.0 slots will be with zero to negligible. So you won't miss out anything substantial.
Cheers!