Los Angeles, I've been here 10 years.
Yes, it is frickin' hot here in August and September so be prepared.
The Orange International Street Fair is that same weekend (City of Orange) and is quite a good time for the price. It is close to Angel's stadium and Disneyland. I would agree that Disney is overpriced but it is easy to stop at Downtown Disney for trinkets and eats only.
Hertz is offering free Gold Member enrollment right now for those renting cars. Also, use the CDP 1736927 upon reservation for 15% off the rental and discounts on the optional coverages. There is a reason rentals are much cheaper here than in MN, there isn't any coverage mandatory for rental companies; consider the LIS and LDW coverages and don't get screwed.
The Getty and MoMA are both excellent museums worth an entire day. Next, don't go to CA and not stop by the Hollywood walk of fame, find your favorite star or whatever, see some of the bizarre people that LA has to offer.
For walking and shopping Santa Monica and Pasadena are the best. I live in Pasadena and love it, it's no Minneapolis but there's art, movies, restaurants, free concerts in the park, etc. Parking sucks so read the signs carefully, some meters are active 24 hours a day and others until 8 or 10pm, the Gold Line also goes there. A hotel downtown will give you the best train access but they shut down before midnight every night.
Remember, USC and the stadium are in South Central, not the most tourist friendly zone. Also, avoid the 5 and 405 freeways if possible, even on Saturdays, and yes, everyone here says "the 5." Oh yeah, there are also a miriad of casinos and horse tracks in town if you are into that sort of thing.
Finally, if you are downtown go to Langer's Deli at 7th and Alvarado and order the Mychal Thompson! See you at the game!