I have dreams about the guacamole. Get the sampler, you can't go wrong. I personally cannot vouch for the white chocolate one, but I would try it if given the opportunity. That's how much I trust this place!
Taquitos are always a win... my favorite is the duck (pato).
The drinks are all really interesting and delicious too. Love the carrot margarita.
The servers are friendly and knowledgeable but I cannot say the same for the hosts (or whoever answers the phone). I was calling a week ahead of time to make a reservation on a weekend and little did I know, Momocho is completely booked on weekends. The person on the phone was rude to me and totally unhelpful.
That's not going to stop me from going back again and again, but I probably won't try to make reservations on the weekend for a while...