I suggest staying in Los Angeles for the night...you're going to get the best accomodations hands down. Check Hotwire or Travelocity for great deals in LA.

The drive to vegas on Saturday morning is always better than Friday night...You can hit a lot of traffic just trying to get out of LA county, especially at 6pm. If I drive on Friday, I wait until at least 10pm to leave. Saturday morning drives are always enjoyable,,,,no traffic,,,and the CA desert is beautiful in the daytime. Ive probably made 100 drive trips from southern ca to vegas in the last 4 years, I will very rarely drive on Friday night. Friday night could take 8-10 hours - Saturday will take 4 hours tops...Ive made it in almost 3...(going really fast).

hope this helps, I have never flown to vegas...I enjoy the drive.

Jeff King