Dice, slot machine, roulette, plinko, blackjack are all easy, intuitive games suitable for newbies.
I don't think Blackjack is so easy than Dice and the slots.
[...]Blackjack rules are easy to understand, in short time anyone can play it.
But I agree that the complexity of the game in relation to dice or slot machines is figuring out the odds of winning or losing a game, in Blackjack there are much more odds and math to do.
On the other hand, slot machines give the player much more chances to win too, which can be another "problem".
Each game has its own peculiarities, but in general, I find all the ones that are listed to be easy to play.