The best Tarot deck to use for any particular reading will probably be related to one of the two following reasons.
Some readers are particularly attracted to certain types of Tarot decks, and would prefer to always use their favorite decks to do readings. I have an affinity to the Crow’s Magick Tarot and use it frequently for most of my readings. However, I do occasionally pull out the traditional Rider-Waite Tarot deck and use it when doing a reading for someone else because they are more familiar with the images in that deck.
The second reason to choose a particular Tarot deck would be closely related to what kind of reading is to be accomplished. If a reader is primarily interested in health and healing, then the Medicine Woman Tarot or the Shaman Healing Tarot would be a wise choice for those readings. These are but two of the many decks that can be used for health and healing as there are quite a few in print to choose from.
There are many themed sets currently on the market to select from, and the one chosen for any specific reading should reflect the feelings, emotions, or the reason for the reading that are being exhibited at the time of the reading. Sometimes, it might be just as prudent to use whatever deck is at hand.