Grandmaster -
That sort of question always puts me in a corner. There are several states which offer a 60% payout percentage on their Pick 3 and Pick 4 games (IA and KY, for instance); most hover around the 48%-50% range. A lot of games have pari-mutuel payouts, and the payout percentages for those are set by state law. Most states' largest games offer variable jackpots, and the payout percentage for those games is dependent on the size of the jackpot.
But, if I had to pick one game in the U.S., and one game only, it would be MA's Cash Winfall. With the base jackpot, the game has a payout percentage of 59.51%, and rollovers will increase that.
The best consistent payout percentages on any game I've researched so far, though, have to be the Western Canada and BC 6/49 games. With identical payout structures they offer a payout percentage of 65.38%.