Did Romeo and Juliet win or lose? Please provide at least two quotes to support an answer.
I think you are asking if they won or lost at the game of love. I think you could look at it both ways. For example, take this statement:
Ah, dear Juliet,
Why art thou yet so fair? shall I believe
That unsubstantial death is amorous,
And that the lean abhorred monster keeps
Thee here in dark to be his paramour?
For fear of that, I still will stay with thee;
And never from this palace of dim night
Depart again: here, here will I remain
This is from Romeo's last few words before he kills himself. He is noting that Juliet's beauty has not died with her death and he may never get to experience that since he is about to kill himself, this could be considered a great loss. On the other hand, he is in the same quote vowing to stay with her. This could be great victory because when they are both dead, at least they are dead together.
Another place you might find victory is in the last few lines of the entire play. Capulet essentially grants permission now that they are dead. He allows Romeo's body to stay in the tomb, thus the lovers are allowed to be together and the feud is now done, a victory of another sort indeed.