My DS looked outdated even when I got it
My 3DS was nice even when I was playing it in 2018

So 3DS

Based on my experience, I will say Switch easily.

If we are talking dedicated handhelds however, I will go with the GBA.

No worries, like I say it was also cos I didn't want 90% of the thread to be the same overdone arguments about whether Switch is a handheld or a console or a hybrid haha.

And yeah I could only play my 3DS for like 20 minutes before my hands started to cramp haha. Dunno how I'd go with Gameboy/GBA/DS in this regard as I never owned them. I got big hands, and as I was never allowed to have a portable growing up, gaming became defined as a big screen experience for me and so that's what I prefer.

The DS, it was easily the most versatile and revolutionary system. While it was underpowered spec wise, it's touch screen concept was way ahead of it's time and created new gameplay possibilities. Also a strong library.

Gameboy. Because nostalgia... And the insane battery life that seemed to last longer than even a games controller these days.

It is :)

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.

Switch lite because its my first nintendo handheld.

Two portables of the past ever tempted me almost enough to buy them, PSV and DS, so if we consider Ninty only, my answer is DS. Sometimes I played with my sister's GB and with the one of a ex-gf of mine, but I liked it for a while, then it started annoying me, OTOH, DS was very promising both for gaming and other things, before buying my first cheap tablet, I even considered buying a DS instead, also to use it as a tablet, but before I could finally decide, Ninty ditched it for 3DS, that I never liked at all, so I eventually bought the first tablet that offered me enough for not too much money.

1) Nintendo DS. The system was so revolutionary and there were so many innovative and great games for it. If feel that in a few years (after the 3DS has been properly phased out) the DS library will grow in popularity again, as dual screen gaming is so unique. The DS had a lot more games that used its unique features than the 3DS. You can't scratch that itch anywhere else, only on DS (and 3DS, but that didn't make use of the dual screen, touch screen and microphone that much).

2) Gameboy (Color). The Gameboy was just amazing back in the day. Playing Mario, Zelda and later Pokémon on the go was great and the system had roughly a decade to build its impressive library.

3) Gameboy Advance. The GBA got many great titles and would be considered on of the all-time great consoles today if the DS hadn't been released so early. Great system.

4) 3DS. The weakest Nintendo handheld for me. It was based on a gimmick most people didn't want to use and I distinctly remember the original 3DS model being a step down in build quality (end even screen size) from the DSi. The 3DS has many great games but it didn't reach the heights of the other handhelds for me.

If the Switch was included it would probably tie with the DS for me right now. But it still has a lot of time on the market left.