Super Mario Bros, CS 1.6 if you lucky on medium/high LOL
Your CPU is nice, GPU 7870 is somewhat similiar to nvidia 660ti which is nice too,RAM is enough for few years.
You can check on http://www.systemrequirementslab.com/cyri
just search what game you wish to play and click Can you run it.It will tell you what can you run. But you shouldn't worry,you can run any new game on high res