The Wii was good. Had a vast library of good exclusives, had backwards compatibility with Gamecube, was hackable so you could pirate everything. Some of the best games for it had Gamecube controller support so if you didn't want to waggle, you didn't have to. And the good games that actually had forced waggle actually used it well, like Red Steel 2, MadWorld, and NMH 1&2. The DS was also great. Had backwards compatibility with GBA, had a great exclusive library of it's own, had flashcarts so you could just pirate everything. Second screen came in handy for displaying menus, maps, and inventory. Or even having tate gameplay like Contra 4.
3DS, I don't really like as much. I mean, the ease of piracy was cool or whatever, but it's library isn't really that impressive. Mostly just ports from previous gens, honestly (OoT, MM, Star Fox 64, Tales of the Abyss, Soul Hackers, Mario & Luigi 1&3, Devil Survivor 1&2, Luigi's Mansion, Radiant Historia, DKCR, Xenoblade, DQ7&8, MonHun 3, MGS3, SSF4, etc. The original DS had it's fair share of ports, too, but the 3DS seems like it's more ports than original titles. The Wii U was pretty damn good. Easy piracy, tons of exclusives (at the time. They've since been ported to Switch), Pro Controller had god-tier battery life (still unmatched), you can add in Gamecube backwards compatibility by hacking, etc. Hell, even some of it's exclusives aren't yet on the Switch like W101, Pikmin 3, and Xenoblade X. I never got the hate for the Wii U.