If we're judging by sales, no. If based on things like critically acclaimed games and new hardware being successful, 2017 is a good year for Nintendo, but not their best.
1986 - Though the Famicom had been out for a few years already, it only got Super Mario Bros and notable third party support in 1985. 1986 is when the system really hit its stride, with Nintendo releasing the Disk System multiple groundbreaking games. The Legend of Zelda, Metroid, Kid Icarus, and Mysterious Murasame Castle all came out in 1986. And with this new wave of hits, third parties released some of the biggest games of the era. Dragon Quest, Ghosts n Goblins, Castlevania, and Adventure Island came out this year. And although 1985 was when they had a limited NES launch, 1986 was when the NES properly hit the American market.
1992 - Though Nintendo was late to the 4th generation party, 1992 was probably their best year during that era, if only because a number of modestly good things happened that year. For one, 1992 was the year where their hardware was selling its best. After letting Sega beat them to the punch with the Genesis, 1992 was when the SNES began to match and/or outsell it in many places. This was also when the Super Famicom began to crush the PC Engine in Japan. As for games themselves, Nintendo did a decent job at juggling the SNES, Game Boy, and NES. Super Mario Kart was one of the system's biggest hits and started a subgenre. The Game Boy got Kirby's Dream Land, another big new hit, and Super Mario Land 2, which sold over 10 million copies and was far better than the 1989 original. The NES still got a trickle of support, thanks to multiplatform titles like Yoshi's Cookie. Also, the SNES got Street Fighter II in 1992, and that was probably the biggest pseudo-exclusive Nintendo ever had.
2001 - Though Nintendo had some high points during the N64 era, there was almost always something going horribly wrong. For example, during 1997 in Japan, Pokemon was making the Game Boy stronger than ever, but the N64 was already declining due to a lack of quality titles. 2001 though was one of those years where Nintendo managed to pull off two generational transitions successfully. The older systems still got a few good games, like Animal Forest, Dr Mario 64, and the Legend of Zelda: Oracle duo. But first they managed to launch the Game Boy Advance worldwide, to widespread success, with loads of great games out the gate. Advance Wars, Golden Sun, Mario Kart: Super Circuit, Super Mario Advance, Wario Land 4, and F-Zero were all there, along with the surprisingly robust library of third party games. And later in the year, the GameCube had reasonably successful launches in Japan and America, with plenty of great games in the launch window (Super Smash Bros Melee, Luigi's Mansion, and Pikmin). The next few years weren't great for Nintendo, but this was promising.
2007 - This was the year where the philosophy behind the DS and Wii was most clearly showing its benefits, and was also one of Nintendo's best years in terms of sales. The DS, which needed the Lite redesign to really get going, finally had all of Nintendo's flagship series on it, with the release of games like Mario Party DS and The Legend of Zelda: Phantom Hourglass. And Pokemon DP in the West. Meanwhile on the Wii, people turned out to still be interested after the first few weeks. In Japan and North America, the Wii was Nintendo's biggest console since the Super Famicom in 1992 and the NES in 1989 respectively. More importantly, Nintendo kept on releasing games that either justified the concept of the Wii, benefited from it, or at very least weren't hurt by it. Super Mario Galaxy is the most acclaimed example, but you also had Mario Party 8, Wii Fit, Super Paper Mario, Metroid Prime 3, and Mario Strikers Charged.
Nintendo in 2017 is doing fine, but their lack of 3DS support is holding them back a bit.
