Going to have to go with DS and the original Gameboy. Both were revolutionary in their time. While Gameboy was an interesting step, it lacked the revolutionary feel, and it had massive issues with how dark the screen was, making some games very annoying to play (Circle of the Moon comes to mind). Similarly, 3DS had a flawed glasses free 3D viewing experience where the user needed to look at a specific angle. In addition, while DS was a shining beacon for handheld gaming of its time, 3DS fell behind mobile in quality.
In terms of game libraries, the DS, in its time, had an impressive one: beginning, revolutionizing, and resurrecting several genres.
It brought RPGs back to the forefront, along with adventures and 2D platformers; virtually created the casual genre (not as in games for retarded people, but games which you login and play for minutes a day over long periods of time). Prior to that time, they had been on the decline with only a few RPG franchises being viable, and traditional ones like Final Fantasy on the steep decline. But anyway, here's some of what DS brought:
* Chrono Trigger DS
* Dragon Quest 9 (first exclusive handheld Dragon Quest)
* Dragon Quest 4 remake
* Dragon Quest 5 remake
* Dragon Quest 6 remake
* Final Fantasy 3 remake (probably the small snowball that brought interest back to turn based/ATB RPGs)
* Final Fantasy 4 remake
* Phoenix Wright: Ace Attorney (a game that turned out to be WAY bigger than predicted, was DS's Earthbound, resurrected the adventure genre)
* Phoenix Wright: And Justice for All
* Phoenix Wright: Trials and Tribulations
* The World Ends with You
* Radiant Historia
* Shin Megami Tensei: Devil Survivor
* Valkyrie Profile
* Rune Factory 3
* New Super Mario Bros (The game that brought 2D platformers back to the forefront)
* Kirby Superstar Ultra
* Sonic Rush
* Brain Age (not only kicked off the casual games genre -which exploded immediately, but found its home on mobile- but also the touch screen interface for games which is now commonplace)
* Animal Crossing Wild World (took Animal Crossing to the platform type it was born for, handheld)
* Super Mario 64
* Professor Layton and the Curious Village (and 3 sequels)
* Elite Beat Agents
* 999
* Ghost Trick
* Hotel Dusk
* Last Window (Which, IMO, is superior to Hotel Dusk, and one of the best classic adventure games of all time)
* Another Code/Trace Memory
* Disgaea DS
* Contra 4
* Rhythm Heaven
* Infinite Space
* GTA: China Town Wars
* Mario Kart DS (this was the break-through Mario Kart title, that took the franchise from a mere tower, up into the stratosphere)
* Trauma Center
* Advance Wars: Dual Strike
* Metroidvania games (While the Metroidvania series began on PSX with Symphony of the Night, the popularity of that series peaked on DS)
The DS is the most critical and commercially successful dedicated handheld in history. It is the best.
I describe myself as a little dose of toxic masculinity.
