My NES, SNES, N64, GCN, Wii, Wii U, GB, GBC, GBA, OG NDS, DS Lite, and OG 3DS all work fine.
Only my DS Lite and Wii ever needed servicing (DS Lite had a wonky shoulder button which I fixed myself, and Wii had the overheating/graphical artifacts that Nintendo had to fix).
My 3DS has the screen marking thing because of how it closes, and that's just "poor design" - but really, I don't care because the machine works perfectly no matter how many times it's been dropped, thrown, or otherwise abused.
Conversely, I've never owned one Playstation product that didn't have some legit problems (PS1/2 disc reading issues - remember flipping PS1 upside down to read discs?, OG PS3 YLOD issues, PSP 1000 fucked-up d-pad/Square button), and my 360...well, you already know about those.
Nintendium is still used in these products (even though it's less than before since DS/Wii, IMHO).