I'm a bit conflicted here.  On one hand, the Switch is already my favorite game system behind only the SNES and the NES (as of right now). There is just so much frick'n content I love between original titles, remakes/ports and arcade ROMs I can play anywhere.

On the other hand, I don't like choosing a game system that is not finished yet since my top 5 games could obviously change.  That, plus the fact that I already know that the Switch is going to win this in the poll makes me want to pick the DS instead.  Furthermore, the touch screen revolution was such a blast and I adored the beautiful design and screen of the DS Lite.  I bought a total of four DS systems in its life and didn't even own the DSi (the original, a white Lite, a black Lite and finally a Zelda gold Lite).

However, because my single favorite game series, Zelda, left such a bad taste in my mouth on the DS due to the deplorable control method coupled with the fact that the games weren't great anyway, I'll opt to just vote for the Switch  since I skipped it in the console thread.

Top 5 Switch games so far:

1. Zelda: Breath of the Wild
2. Mario Kart 8 Deluxe
3. Super Mario Odyssey
4. Zelda: Link's Awakening
5. Metroid Dread

The OG Gameboy.

It says allot when you get a dozen of us nerds in a room, all linked up/networked and playing Pokemon Red/Blue in the 90's.

That wasn't an experience that would be replicated in console land until the OG Xbox and Halo.

Well if we're counting the Switch it's not a hard choice. Otherwise it's a very close call between GBA and 3DS. My full ranking would be:

1. Switch
2. GBA/3DS
3. NDS
4. GBC

When it comes to games, I think I've listed my Switch favorites a few times before, so I'd rather name some GBA and 3DS favorites instead:

GBA: Pokémon Ruby & FireRed, Golden Sun 1 & The Lost Age, Metroid Fusion and Mother 3.

3DS: The Zelda Remakes, Zero Escape: Virtue's Last Reward, Metroid: Samus Returns, A Link Between Worlds and Pokémon X.

The Switch, of course! I also have a great fondness for the GBA for the Metroid and Castlevania titles. The DS had a few titles I enjoyed, but I never personally purchased a system. I don’t really use the Switch too much as a handheld, though, so I picked the GBA.

Gameboy Advance. It was straight up core gaming at its very best. The DS had a wider library and was obviously a more capable machine. But when it comes to core gaming, it's hard to beat GBA. It's also the last of the Gameboy line, as well as Yamauchi's last handheld contribution, so it's gotta get my vote.

3DS was the first Nintendo handheld with good quality 3D graphics. That’s why it wins for me. Never owned a switch.

I will vote for 3DS only because I see Switch as hybrid

Much like Switch is my favorite Nintendo console, it is also my favorite Nintendo handheld. Never really got into handhelds much after the gameboy outside of Zelda titles. However the hybrid functionality that lets me play full console games on the go, and resume on my TV at home seamlessly has me using it on the go even more than my gameboy itself back in the day.

An undocked Switch blows away every other handheld.

Other than that, I'd say the 3DS. The OG Game Boy will always hold a special place for me, though.

Since I already answered this question for Switch when favorite Nintendo console was discussed, here are my top 5 Game Boy games.

1. The Legend of Zelda: Link's Awakening

2. Metroid II: Return of Samus

3. Kid Icarus: Of Myths and Monsters

4. Pokemon Red/Blue

5. Final Fantasy Adventure

This question is rather difficult for me to answer even when I played a lot on each handheld system. The first system I bought with my own money is the GBA and that will always have a special place in my heart. Playing Mario Kart and Advance wars with friends using only one cartridge was great.

The original game boy is the system I blame for my love of gaming and handheld gaming in particular. There is something special with sitting at the exact right place under the lamp to get the clearest picture while trying to retain my castle in Mario Land 2 six golden coins.

For some reason, I never got to play much on my 3DS. I still have a few games that I never finished but also never feel like playing. i figured that maybe I finally got old enough that games don't interest me anymore. Or maybe just that handheld gaming stopped being fun since I still played a lot on other systems.

But then the Switch came along and I once again spend hours and hours in my sofa playing. It is my currently most used system and would be the system i picked if i only ever got to use one system ever again. With the switch my love for handheld gaming resurfaced. It will still probably be my last dedicated handheld platform since my mobile is enough for my gaming needs on the go.

But I will give the victory to the system that i have bought most copies of, DS and more specifically DS Lite. I still play it now and then using my third system and got a new and unused system in a box when the current DS Lite gets to old. What strikes me however when I play the DS is that I actually often use it to play GBA-games, mostly advance wars and fire emblem. But in the DS prime both me and my girlfriend at the time spent whole weekends in bed playing pokémon together and brought it on picnics and to the beach. Great times.
If I owned a GBA-micro, that might have kicked DS down to second place. I love that little system, the screen is so crisp. But DS takes the top spot for me when it comes to Nintendos handheld systems.

Top DS games
1. Phoenix Wright Ace Attorney (all of them)
2. Advance Wars Dual Strike
3. Hotel dusk Room 215
4. Elite Beat Agents
5. 42 all time classics