I asked some of the QA's I work with and some of them mentioned their previous experience beta testing games.
I don't know your background but have you done anything like that? If so just mention the game(s) you've done open betas on. If you didn't come across any issues, were there some that other testers did that you could mention? How were bugs reported to the developers during the testing?
Now if you haven't done any of that and they are just looking for any released games you've played and have noticed bugs in, I think they are just looking for clipping issues, horrible camera issues, bad pop-in/pop-outs, lag and horrid framerates. Just bring up any games you've come across that have had issues like that's affected your gameplay experience.
Hope that gives you some ideas and
![G o o d [Good]](/emoticons/g_o_o_d.gif)
luck!!