IMO stay in Pasadena. Stay at the huntington. I got married here, it is wonderful.
http://www.langhamhotels.com/en/the-langham/pasadena/
Go out to either Shiro's and Bistro 45 if you feel like something wonderful and romantic.
https://restaurantshiro.com/
www.bistro45.com/
Both better options than what you will find in Korea town(unless you are really in the mood for korean food) or downtown LA. Downtown LA has improved drastically in the past 12 years but it is NOT really spending a night with the best LA has to offer.
Look, you are away for your kids for one night only, make it delish and relaxing. Stay in Pasadena and enjoy yourselves. You can't see the best of LA without a car so just don't try. You will very much enjoy Pasadena however if you go where I've told you.

Ending the night with drinks on the patio of the Huntington is hard to beat...