It really depends. Some people may like harder cards like Aladdins, others may like softer cards like tally and arrco. Some may look for cards with good design and nice handling, for example the smoke and mirror cards by Dan and Dave.
I would suggest you try to get various decks of playing cards and find the one you like the most. But in my experience, every deck of cards has their own feeling and it really doesn't matter which one you use as most of them feel nice. If you have the technique then you can do good flourishing, which type of playing cards you use isn't that important/