Truly dry? No, haven't seen one of those yet. Every dry snorkel I have ever seen will let some water in sometimes. I'm sure someone will correct me soon though.
I can't really recommend one because I don't recommend any of them, not even the ones I sell. Every one I have sold came with a suggestion to try a semi-dry instead.
Why don't I like them? They have moving parts and moving parts have the possibility of failure. I have seen them fail open, closed, and partially closed. The moving parts add to the cost, size, and weight.
The worst thing about them is believing they will never get water in them and not being prepared for that sudden gulp of water.
The dry snorkel is a good example of why you shouldn't try to replace training with equipment. If the equipment isn't really really good you get disappointing results. Yes I realize nobody wants to do any training just to snorkel an hour on vacation.
If you insist on a dry snorkel just go with one of the major name brands from a dive shop and don't be afraid to spend some money on it. The cheaper off brands will definitely fail more often than a high quality model. If you aren't shocked by the price of a dry snorkel you didn't get a good one.