I'll be in Cancun next week. I usually have 4 or 5 shops that I frequent every time I'm there. Post your e-mail addy and I'll give you a full report when I get back.
There is a LCDH in the Flamingo Plaza. However, the last couple of times I've been there, the cigars were crap. Spider webs on the boxes (no kidding), torn wrappers, etc. I hope they have improved things this year, but I'm not expecting much.
There is another shop I found last year that I was very impressed with. Cigars looked legit. Picked up a few Bolivars and they smoked perfectly. The store also had a cigar roller depending on when you go. I missed him last year by a few days. Cant remember the name of the store, but I'll let you know when I get back.