I would try for John Wayne. It's the closest and it's easy to navigate. Long Beach is also a good choice, but it's a smaller airport. Tickets prices are probably higher because of that. LAX is, well, LAX. I grew up in So Cal and I HATE LAX. Way too many people, I don't like driving around/through it, security check lines can be real long. Tickets are probably cheapest through LA, but think about your time also. Ontario isn't a bad choice, but it's further from DL. Burbank will cause you to drive through LA traffic. Hope this helps.