Games Pass offers Microsoft's entire first-party lineup of Xbox One titles, brand new first party games at the day of release, XB1 games released across the generation, and dozens of backwards compatible 360 and OG Xbox titles. It costs $10/mo, and often drops down to substantially lower prices when on sale. I got 6 months for $30, for instance.
PS Now offers a handful of Sony's first party titles on PS4, and nothing too recent. Much of its PS4 offerings are sub-par, and while its PS3 collection is expansive, many of the games on offer demand far greater reaction speeds than the input latency of streaming allows for (such as the many fighting games on the service). It costs $20/mo, $45 for three months, or $100/yr. Very rarely are subscriptions offered on a discount, and they are never steep when they do happen.