First of all, THANK ALL OF YOU SO MUCH!! That means all of you folks who helped me with suggestions and links, the people at LA Taco Review, and extra-special thanks to Bandini, whose "Great Taco Hunt" was where my search began in earnest.
While my trip was cut short and ended up being only 3 days, I was able to get in a taco or two in that time. Here are my impressions:
TACO MIENDO in Culver City - This was my first stop off the plane and on the way to the hotel. Wow - the tacos were so good here that they absolutely set the tone for a great trip right off the bat. I had two Asadas and a Pastor, and the asada was truly outstanding. The hand-made tortillas are something that I simply cannot find in Detroit, and the flavor of the beef was close to the best that I had ever tasted.
RICOS TACO TRUCK at Venice and Melvil - Unfortunately, this one didn't work out quite as well. I had two each of the Asada and Pastor. All four fit side-by side in the bottom of a sandwich bag, and feeliing the weight of the bag I thought maybe there were only two in it. When I got to the car I discovered that there were indeed four very small tacos with not much meat at all in them. Also, for some reason I didn't get any of the usual condiments with them. The flavor of the asada was nothing special, and the pastor was pretty good but quite greasy. Now I should say that I went to this truck after the Super Bowl, during which I had consumed a lot of beer. So in all fairness, I may give the place another try on my next trip. (disclaimer: even the lowly Detroit-area tacos usually taste fantastic to me when I've been drinking.)
TACOS POR FAVOR at Olympic and 14th. - Amazing tacos! The Asada was up until that point the best I had ever tasted. And the Carnitas were equally delicious. I asked the gal at the counter if she thought I should get the Carnitas or the Pastor, and she enthusiastically said the Carnitas. She wasn't wrong! We also had the chorizo and cheese tacos, which were pretty interesting. My dining partner, who lives in Santa Monica, was also very impressed with the Asada. Life is very good - its a sunny and warm day, and I've just had the best tacos in my life.
ARANITAS and CARDOZA trucks on Mulholland east of the 405 - Before heading to my hotel in W. Hollywood on the 3rd. night, I decided to make the drive up to Mulholland and across to Laurel Canyon, then back down into town. Based on LA Taco Review's write-ups, I figured I couldn't go wrong with these two trucks. Sadly, much disappointment was in store. I got to Aranitas first, at like 1:30 pm. They were out of Asada, so I ordered a Pastor taco, which was OK but nothing great. Then over to the Cardoza truck, which was honored "Top Truck" by LATR. The single Asada taco that I got was quite frankly one of the absloute worst that I had ever eaten. The razor-thin dried up piece of meat looked like a slice of beef jerky, and was pretty much that dry. I think maybe it was left over and had been sitting there for quite some time. I also remember the salsa and condiments not being good enough to improve it at all. Wow - shockingly bad! I was the last customer of the day (didn't realize that they closed at 2p.m., not a.m.), but to me that's no excuse for serving such a substandard product.
EL PARIAN on Pico near S. Union - Well, this is it, BY FAR the greatest Asada taco I've ever enjoyed. I was still full from lunch, so I only ordered one. It arrived with pico de gallo already on it, and on first bite I must say that I couldn't believe that a taco could be this sublime. Perfect might even be too weak of a word, it was that good! So the waitress comes over just to confirm that I want another one, not to ask. YES!!!! Absolutely!!!!! The grilled chunks of perfectly seasoned steak are jucier than I've ever had on a taco - and I mean natural juices. While there is not a trace of fat on the meat, they must be grilled with some animal fat because of how beautifully moist they are on the tortillas. Those were the last tacos that I had in town, and I left knowing that it was HIGHLY unlikely that there were any better to be found.
It's interesting - I went on this trip thinking that the tacos from trucks were the best around, but my experience here was EXACTLY the opposite. The taquerias in L.A. rule, at least in my very limited experience. There are quite a few places that I didn't get a chance to try and that I will on return trips. The problem is that I had three Japanese meals with the friend that I was visiting, leaving that much less time for tacos. Next time I'm in town I will definitely try King Taco, Tacos Baja Ensanada, El Taurino and a few more of the trucks and some of the places in East L.A. that I haven't seen much about on the English-speaking websites.
As far as my Japanese diversions, I should note that I had very good Chicken Cutlet Curry at Hurry Curry and fantastic Ramen at Chabuya (both on Sawtelle).
So in closing, thank all of you again. I never would have discovered these places were it not for your help.