Never owned anything Nintendo prior to a Wii, but currently have a DS lite, 3DS, 2DS, Wii and Wii U. The Wii had some insane usage, and only needed to send it back once for repair, and that was just to have its reader cleaned. It still works absolutely fine.
The 3DS has suffered some falls down the stairs and there's not a mark on it and it still works perfectly. The DS went in for repair a couple of years back because the charging port started to loosen, but once that was fixed it worked and still continues to work well.
2DS hasn't had so much heavy usage so it's difficult to say, but it's supposed to be the most robust of the lot in terms of surviving damage.
The Wii U has worked faultlessly since we got it 2 years ago. The Gamepad has survived being sat on, squeezed between sofa cushions and dropping. I had an intermittent problem with one of the Pro controllers which seemed to clear itself (one of the sticks kept transmitting left) but since that was bought separately, I don't think that counts.
All in all, I'm more than satisfied with the durability of the hardware of all my Nintendo devices, and with the excellent repair/support.







