Bicycle Prestiege (Bridge Jumbo) - My favorites. Ignoring the price, they are still my faves. Hard to beat great cards at a great price.
Copag (Bridge Jumbo) - I know these are the bargin basement of plastic cards, but I love how flexible they are. When teaching new players how to riffle-shuffle, there's nothing easier than a card that bends like paper, but just snaps right back. If they wore differently, I'd rate these #1.
Do not like...
KEM - maybe I'm just unlucky, but every deck I've used has been tacky and slightly warped. The deck I have at home is USPC, and I know these are worse than the cards manufacturered before the United States Playing Card company bought them, but I'm not likely to get pre-USPC without a time machine, and if I had a time machine, there are a lot more changes I'd need to make before buying cards.
Paper - Just needs to be said. I still have like a brick of paper cards somewhere, just in case the niece and nephews come over and want to build a house of cards.