The best is to drive a little further to Calandros on Perkins/Siegen. I havent been into Cuban's either but I have never been terribly impressed with Marcello's. Albertson's may have a better selection than that place.
I agree that Calandros has a better selection than Marcellos and I also have not been to Cuban (since it has been opened again as Cuban). I'd like to know which Albertsons is better than Marcellos though.
One other spot you might check out is Mathernes (Perkins and Bluebonnet)....Might not be quite the quantity that Calandros has, but I could swear I have seen some nice beers there that are not at Calandros.
Oh and I can probably vouch for the others on the board by saying, go to the Calandros on Perkins, not Government.