I know it isn't *quite* the same, but from the 3DS to the Switch is probably the largest jump Nintendo has ever made. From a resolution perspective alone it's a 4.8x leap. Not to mention what the Switch is actually capable of. 3DS struggled with a downscaled port of a Wii game (Xenoblade) and required better hardware (e.g. New 3DS) whereas Switch was able to handle a downscaled port of a X1/PS4 game (Witcher 3)

As a 10 year old kid, the SNES simply blew me away compared to the NES. For people who didn't grow up with that era of gaming, the jump in color depth may not seem like much today, but it was massive at the time. Couple that with stuff like parallax scrolling, Mode 7, and much better audio, but also keeping the style of games I loved, it was perfect.

I know a lot are saying the jump to N64. Yes the bump in horsepower is massive, but even at the time, those graphics were pretty ugly, and time certainly hasn't been kind to it. I was a heavy PC user, so that style of graphics wasn't new to me. That coupled with a horrible lack of games meant I skipped that generation entirely.

SNES to N64 and 3DS to Switch

I feel like people are cherry picking by saying 3DS to Switch lol. Switch is considered the next gen to WiiU, not 3DS, though since it is hybrid and technically its just a handheld with a dock link up to TV you could say its the next gen for both WiiU and 3DS. But Nintendo already had a much much more powerful system out when the 3DS was out - the WiiU - so I wouldn't say 3DS to Switch counts. Furthermore, Breath of the Wild was a cross gen game shared between WiiU and Switch, not 3DS and Switch. Also a bunch of WiiU games have been ported to the Switch, aka last gen games ported to current gen, the same is not true for porting 3DS games to Switch. Finally the point is further made by the fact that Switch costs in the $200+ range like Nintendo consoles normally are, and not the <$200 range like Nintendo handhelds normally are.

Most people view the Switch as Nintendo ending its handheld-only line of systems (GB, GBA, DS, 3DS) and moved its console line to be a hybrid so that Nintendo didn't need the handheld line anymore. 3DS to Switch is not one of the generational leaps.

SNES to N64, IMHO, was the biggest jump in technology in gaming history. 2D d-pad to 3D analog... no jump has even remotely touched it. Mario 64 forever changed gaming.

I feel like GBA SP was the beginning of Nintendo’s new style choice that became prominent in the Wii/DS era (with the DS Lite, at least). But I completely agree on how important those two features (backlighting and internal battery) were to the handheld experience. Game Gear had done backlighting before, but it ate 6 batteries every two hours to do it.

Completely agree, the GBA SP felt like it created this new template for Nintendo's future handheld consoles.

I remember the Game Gear was the first to have backlighting and I was telling myself why was it taking Nintendo so long to do that on their Gameboys lol. Yea it was a beast at sucking up a lot of batteries fast. +A effort for Sega trying.

In terms of specs...
1. SNES to N64. SNES had a 31x faster CPU speed, and about 40 times more RAM. Polygons were very rare on the SNES, and very blocky. N64 games may have had a lot of sprites, but also had a lot of 3D environments and a shift to polygon graphics.
2. 3DS to Switch: Whether the 3DS or New 3DS, the leap to the Switch is huge. There's a way higher resolution, way more RAM, a way better CPU/GPU, etc.
Honorable mentions: NES to SNES, N64 to GCN, Wii to Wii U

Funny enough, two of the lowest spec jumps Nintendo ever had (if not the lowest) were some of the biggest changes in gaming philosophy. 

The Wii added built in online (Wi-Fi at that), and added motion controls.

The Switch introduced hybrid gaming and easier game development in comparison to the Wii U.

SNES to N64 is a pretty obvious choice. Nintendo also was much more successful moving Mario and Zelda into 3-D where series like Mega Man, Castlevania, Contra, Street Fighter, and Mortal Kombat crashed into the polygon ceiling,

I'm also going to say 3DS to Switch was a pretty huge leap, not just graphically but for the "switching" ability.

Gamecube looked like a real improvement over N64 as well, and I think that gets understated. GC is what I'd wished PS2 looked like.

Fun fact: the Color TV Game was the best-selling home video game system of the 1970s, despite being available only in Japan. Nintendo "won" the first generation of gaming.