I've been wondering the same thing myself, and was a little surprised no one had made a thread yet. Was planning to do it myself if no one else did.
From personal experience, Affordable Space Adventures is great. A must own for Wii U owners. I just downloaded Pushmo, and that is a pretty cool puzzle game. I want to check out the other games in the Pushmo series. Pokémon Picross is a great puzzle game if you like Picross puzzles. BoxBoy is a pretty cool puzzle game, and it has a couple of sequels as well that I want to check out. I really liked Fluidity on the Wii, and there is a sequel I am going to download on the 3DS called Fluidity: Spin Cycle
I found some articles out there:
Highlights seem to be:
Super Mario Advance 4: Super Mario 3 (Wii U) for the bonus e-Reader levels.
Xenoblade Chronicles X (Wii U) because who knows if the data packs that improve performance will be available.
Any of the Virtual Console games. Personally, I am looking at stuff like Earthbound and Earthbound Beginnings, Zelda - Oracle of Ages/Seasons - Minish Cap - Phantom Hourglass - Spirit Tracks, Advance Wars Dual Strike, Pikmin 1 and 2, Pandora's Tower, Metroid Fusion and Zero Mission, Golden Sun 1 and 2.
Hard to find/expensive physical games. I've been looking at stuff like Kid Icarus Uprising and Bravely Default on eBay the past couple of days. Physical copies seem to be going for the same or more than digital. I'm worried once the digital versions go away, the physical versions price will go up even more.
Unfortunately, I am probably looking at spending $200+ across both shops before they shutdown.
If anyone finds other articles, please post them.
Switch Code: SW-7377-9189-3397 -- Nintendo Network ID: theRepublic -- Steam ID: theRepublic
Switch - Super Mario Maker 2 (2019)
Switch - The Legend of Zelda: Link's Awakening (2019)
Switch - Bastion (2011/2018)
Switch - Mario Kart 8 Deluxe (2014/2017)
3DS - Star Fox 64 3D (2011)
Wii U - Darksiders: Warmastered Edition (2010/2017)
Mobile - The Simpson's Tapped Out and Yugioh Duel Links