Pick whichever lounge is most convenient to reach at LAX. There isn't enough difference between lounges to be worth going out of your way (they are all sub-standard at LAX). The DL CR is very nice (not crowded due to all the service cuts at LAX for DL) so if you are able to access that it may be the best lounge to use. Often I fly DL into LAX for an international connection just to be able to use that lounge instead of the Bradley lounges.