To repeat or not to repeat

One question I often ask myself at each careyoke night is whether or not I can repeat a song that I've already done. Sometimes I think, that one got a good response, perhaps I should sing it again. I do indeed enjoy positive feedback. (Love me!) However, other times I think, I don't want to be boring or predictable or get stuck in a rut and defined by certain songs. I also like the challenge of coming up with more good songs to do. In fact, if I didn't have new songs to think about all the time, I might actually do something else - like work on my diss. And that would be crazy! But when will it end? Could we possibly do all the good songs that there are to do (at least on the Kid's list)? Will I be boring if I repeat past songs? Or are some performances worth repeating? How do I know which is the case? And when does a song become a "classic" that can be repeated (e.g., Total eclipse, Survivor)? Is it a classic if it's on Jeremy's "careyoke favorites v.1.0"? "Sister Christian" got on there and I only did it once. Should I do it again? "Sweet Child O'Mine" wasn't on there but I did that a couple of times - once b/c Jeremy signed us (me) up for it. Maybe that'll be on vol. 2...