Sometimes when a console is replaced it is dropped like a hot potato and gets very little support after its successor hits the market.

Other times though, a system continues to get a decent lineup of games even after being replaced.

PS4/XBO are receiving an unprecedented amount of support after being replaced, but if we look further back, which system before them do you consider to have the best post-replacement games lineup, and what's your argument for why your choice deserves the top spot?

Probably the PS2. The console continued to get support till the PS4 was about to launch lol

Either the NES or PS2.

NES! The last games came in 1996!

I can hardly answer this question that well because most of the consoles with a lot of titles after replacement were ones I didn't play much.
But Mother 3 is one of my favorite games and a lot of other GBA games came out because of the initial "third pillar" approach.
PS2 got Persona 4, PS3 got a cross-gen release of Persona 5.
DS and 3DS still got first-party support, same with NES and SNES.
I feel like I almost have to pick PS2 just because of how much it got. Switch could potentially get one of the best post-replacement libraries to date. 3rd-party ports of older games and small games will likely still come in droves. And I think there's a few unannounced first-party games still coming to Switch. If a new Rhythm Heaven comes soon, I could see it being a Switch exclusive. I wouldn't even put it past Game Freak to have an inevitable Black and White Remake in 2026 or 2027 a Switch exclusive, so they don't need to put in the effort of developing it for Switch 2. You'd still get 2 platform audiences that way because of backwards compatibility, so a cross-gen release wouldn't be needed.

If i had to really pick one it would clearly be the 3DS! It had an unpresidented lineup of exclusives not availible on its sucessor unlike any other system. Lets face it: PS3/ Xbox 360, PS4/ Xbox One where basically 95% cross gen games, wich played better on next gen no one can deny that. 3DS got Hey Pikmin, a game that used both screens of tge 3DS, one of its main features after the sucessor launched! Ever Oasis was a comoletly new IP, Metroid: Samus Returns was an amazing remake, showing the system's power that late in it's lifecycle! It got a new mainline Pokémon game i  late 2017, over half a year after the sucessor's launch, i woukdn't be surprised it this was the best launch for an exclusive (maybe even overall game- GTA V came before PS4/ Xbox One) on a system after it's sucessor arrived! And we got some cross gen stuff as well! It was not before march 2019 when first party support stopped (Kirby's Extra Epic Yarn was its FP swansong- a port but not availible for Switch). There where still reasons to get the 3DS unlike PS3/ Xbox 360 or PS4/ Xbox one expect you wanted cheap asses cross gen games. Ok PS2 got Roge Galaxy and God Of War 2 but besides an (admidable) huuuge 3rd party cross gen support that was basically it- as hard as it sounds! The crown clearly goes to 3DS wich was also the longest produced system of Gen 8! 

I'd say PS2. It got God of War 2, Odin Sphere, Yakuza 2, Persona 3 FES, and Persona 4 as exclusives post PS3 launch. Outside Japan, Persona 3 and Rogue Galaxy also came out after PS3's launch.

Gonna say PS2 as well. In addition to the ones listed above, Sakura Wars was a nice last-minute surprise for the PS2. I still have my collectors' edition of that game.

I have no idea, but I remember enjoying Harvest Moon on the SNES quite a bit when the N64 was already out. So I will choose the SNES. =P

Good picks so far!

Personally I'm gonna go with Xbox 360. After the release of Xbox One it got Rise of the Tomb Raider, Forza Horizon 2, Titanfall, Metal Gear Solid V, Far Cry 4, COD Advanced Warfare, Wolfenstein The New Order, Alien Isolation, Battlefield Hardline, The Evil Within, Sniper Elite 3, GRID Autosport, Assassin's Creed Rogue, RE Revelations 2, Destiny...

Yeah I really enjoyed Donkey Kong Country 3 and Kirby's Dreamland 3 on SNES, both of which launched after it was replaced by the N64.