Newegg offers Tom Clancy's Rainbow Six Siege for Xbox One for $59.99. Coupon code "EMCEMGE32" drops it to $19.99. With $2.99 for shipping, that's tied with our mention from last month as the best price we've seen for this platform. (It's also a current low by $5.)
Need it for PC? CDKeys offers Steam downloads of it for $19.65. That's $3 under our mention from last month and another price low, now by $2.