I also attended Buen Provecho! with two friends (remind me next time to go with LTHers)! Overcoming our slightly divergent interests in places to hit, we managed to stop at 14/28, starting around 5:45 and going until 8:45.
I agree with fusionfan regarding the deliciousness of the mole at Nuevo Leon. I wish we'd hit that up closer to the beginning, when I wasn't soooo full. The chicken volcan at Cuernavaca was also excellent, with a nice hint of heat. The 1/2 price margarita there was HUGE (and probably an error to order, given the stomach room it filled).
Pollo Express would be worth a return trip, as the chicken and accompaniments were all well-seasoned and delicious. Other favorites included the guisado at Perez, the pulled pork at Honky Tonk, and the churros from Don Churro dipped in the Mexican hot chocolate from Jumping Bean.
Lower on my list were the burger from Simone's (to be fair, I'm not a burger person), and I did love the atmosphere of that bar, the horchata that I had been greatly anticipating from Birreria Reyes (it tasted oddly flowery), and the amaretto gelato from Teatro (the other flavors were much better).
We missed out on Take Me Out (Chinese food) - did anyone try the wings? I've heard some good reports.