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Here are some that I have personally used and recommend. I’m including links to bookdepository.com 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.
For beginners
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)
After Tarot 
After Tarot 
Card backs 
Strength 
The Star 
Two of Cups
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.
Modern Witch Tarot (Thick and large cards)
My most favourite deck now! This Rider-Waite-Smith based cards are easy to interpret.
The only downside is that it’s rather thick and large even for my normal-sized hands.
Everyday Witch Tarot (Normal size, Mini)
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.
The Light Seer’s Tarot (Normal size deck)
A deck recommended by @moonchild.rising.
A modern deck with very story-telling cards. I wasn’t a fan of the colour but I played around with my deck and quite like it.
This Might Hurt (Normal size; get it from lovemagicsparkles.com)
I do not own this deck because I feel that I do not need another deck.
But everyone I know who has it, loves this deck. It’s a RWS-based deck with awesome scenes for you to tell stories with.
It’s also really diverse so check it out. It’s an indie deck so you can find it at lovemagicsparkles.com