In theory if blackjack pays 2:1, there's no house edge when using only basic strategy. No advantage play required to break even. General consensus is these casinos no longer exist, and 3:2 is best you can find.

The 2-1-2, or Manhattan strategy rewards blackjack players who hit a good run of hands. The 2-1-2 works a little like the d'Alembert system but instead of increasing your bet after a win, you first reduce your bet. Win again and the bet then increases.