Tough call.
Last generation had a lot of really solid games. Super Mario Galaxy and BioShock rank among my favorite games ever. Microsoft actually had a lot of solid exclusives for the 360; Bungie produced three solid Halo titles, and the original Gears of War trilogy were the first third-person games that (to me at least) felt fun to play. Sony ramped up their first-party output considerably, producing gems like The Last of Us and LittleBigPlanet. Nintendo brought us new ways to play with the Wii's motion controls, and Super Mario Galaxy remains one of the best 3D platformers ever. Third-party titles that really stood out to me included BioShock, Bayonetta, and Far Cry 3. Also, Mortal Kombat was successfully rebooted after some lackluster titles in the previous generation, and Mega Man was brought back to his 8-bit roots for some of the finest old-school-style releases of the generation.
On the other hand, the 360 suffered from serious hardware issues that resulted in abnormally high failure rates (I had to send mine off for repairs twice), and most of MS's exclusives derived from third parties, which dried up quickly halfway through the generation as those third parties couldn't ignore the rapidly growing install base of the PS3. Sony kicked off the generation with an overpriced console, and even after they got to price parity with the 360 once the Slim was released, the PS3 still lagged behind the 360 for most of the generation in terms of online infrastructure, plus the DualShock 3 retained the same clunky, uncomfortable shell the original PS1 controller had. And Nintendo's foray into motion controls, despite resulting in some fun games, were ultimately a novelty that did not move gaming forward in any meaningful way, and in many cases a simple button press would have been preferable to all the "waggle." The Wii was treated by third parties primarily as a dumping ground for shovelware and party games.
This generation, the hardware has advanced enough to where full HD resolutions and 60fps frame rates have become the norm. The amount of polish that newer technology has allowed for has been nothing short of outstanding, seeing as that, in general, 3D graphics tend to not age well. Nintendo has produced some of their best output ever over the past six years, and the Switch is arguably their best console since the N64. Sony has produced what is perhaps their most consistently strong first-party efforts in the history of the PlayStation brand. Sony also kicked off the generation with a system with a reasonable price and a good online infrastructure, plus they finally got around to making a good controller for a change. Since the release of RE7, Capcom has had some of its best output in a while after years of questionable decisions. Doom 2016 was an outstanding reboot, with the focus on gameplay that mixed the best of the old-school with some newer innovations producing some of the most pure kinetic fun I've had in a game in a long time. Alien: Isolation was perhaps the most authentic Alien experience in a game ever, with some solid survival horror gameplay. Indie games have proliferated to a degree never before seen. And the generation (at least on Sony & MS's ends) appears to be ending with a bang, with Cyberpunk 2077, Final Fantasy VII Remake part 1, and Halo Infinite (a cross-gen title) being scheduled for next year, with The Last of Us Part 2 and Ghost of Tsushima being likely 2020 releases as well.
On the other hand, this generation has seen several high-profile games launch in absolutely broken states, at least as far as online was concerned (The Master Chief Collection and Driveclub being notable examples). Arguably predatory business practices pioneer last generation accelerated with aggressive microtransactions and other monetization schemes came to a head with the "loot box" controversy. "Games as a service" is a concept that rapidly spread, with a host of online-only games being produced, including a multitude of multiplayer-only titles and quasi-MMO titles, and frequently plagued by the aforementioned aggressive monetization schemes. Microsoft's first-party output has been less than impressive, with only a single main series Halo title produced (and I don't have a lot of love for Halo 5's changes to the series' core gameplay formula). Nintendo's online infrastructure continues to be stuck in a pre-XBL design mentality.
Overall, both generations have had their fair share of highs and lows, so I think it comes down to the games, and in that regard I think this generation edges out last generation, if only slightly.
