Don't they use six decks now so nobody can count?
Short answer: no.
There are many casinos in Nevada that still offer single deck and/or double deck games. If that is your game of choice, you can play it.
More importantly, the skills required to count cards don't depend on how many decks are used. Adding decks does slightly reduce the player's edge over the house, but it doesn't make counting significantly harder. There are some other factors that make blackjack more difficult to win at today than it was 20 or 30 years ago, but number of decks in play is not the crucial element.
The movie Rain Man contributed to the spread of this myth with a scene in which a pit boss incorrectly states "nobody can count down a 6-deck shoe".