Here are some that I have personally used and recommend. I’m including links to bookdepository.com (affiliate link) because that’s the cheapest place that I know of for decks. You can always get them second hand or at a local bookstore.
I recommend decks that are based on the Rider-Waite-Smith design because this is the most popular design. Most of the definitions on the internet are based on this too.
Smith-Waite Centennial Edition (Normal size, Tin-box size)
I adore the colour of this deck as it looks like someone put an Instagram filter on it.
The back of the deck is a gorgeous blue so they look great when you’re taking photos of it.
I have the tin-box size which is portable and comes with a sturdy metal case.
Radiant Rider-Waite (Normal size, Tin-box size)
A brighter version of the Rider-Waite-Smith deck. There are slight differences from the original–less lines, more roundedness.
After Tarot (Normal size)
Not the original RWS tarot but the meanings are really close. The After Tarot features scenes from moments after the scenes in RWS.
I really like the colour and the changes in the cards, more than the Before Tarot.
Everyday Tarot Mini Tarot Deck (Mini size)
A minimalist version of Rider-Waite-Smith created by the founder of Biddy Tarot (the most popular tarot website). The purple and gold contrast is gorgeous.
Because of the lack in details, I’d say this is more for intermediate readers.
Also, the box it comes with is horribly hard to open. But the card stock is firm and shuffles well.
Everyday Witch Tarot (Normal size)
Not a straight up RWS clone but most of the cards do correspond with Rider-Waite-Smith ones.
The modern images in the cards might make some of you feel more at ease than the stuffy RWS imagery.