I've never been to Disneyland still, but of all people who went both to DL and Universal, about 95% of adults preferred Universal. Therefore, I would suggest going there.
As far as eats go... you say you're a picky eater, but you talk about burgers?

Anyway, In-n-Out is great. Also, make sure you go to Father's Office in Culver City and have their burger with sweet potato fries. Paired with their amazing collection of beers the burgers are easily the best in California.
Also, make sure you get to The Edison in Downtown LA. A little pricey, but their cocktails are amazing and they also have shows and live music. The atmosphere is something out of the ordinary and it's the best bar in L.A. if you ask me.
If you love whiskey, try 7 Grand, which is also a place in Downtown LA. There is nothing spectacular about it, except that they have around 400 different types of whiskey. They have live music on Wednesdays. There is no food served, but you can bring in your own.
I strongly suggest going to see the Toledo show every Sunday night after 10pm at a bar in Santa Monica. The name escapes me, but you can find it easily if you do a search for the Toledo Show on the internet. Be warned: the place is kinda trashy, it's hard to find a place to sit, but the music and the performance make up for it.
Other places to consider: The Bazaar at the SLS Hotel (very expensive), Nanbankan Japanese Grill, Umami burger
For a lazy breakfast, try Olive and Cheese on Washington Blvd near the ocean. As far as I'm concerned, they have the best Chianti in town.
If you are interested in art, I'd suggest going to the Norton Simon Museum in Pasadena, instead of LACMA. While LACMA is bigger, NS has a better collection. And it's near Pasadena downtown, so you can have a stroll there and maybe even catch the happy hour at some of the cafes.
Basically, there are so many places, that it's hard to mention even half. So, explore!
If you want to travel, try Yosemite or Big Bear. Camping there is always fun.
Good Luck and try not to travel from 4 to 7 pm on weekdays.
