My 1tb HDD is 95% full.... of SSB DLC.

Yes because the DLCs they release are basically "Extra Enjoyment" than "Buy this to make the game good/pleasing'"

yes. Mario Kart 8 is pretty much my favorite DLC ever. Cheap and lots of content, and very high quality.

I also enjoyed Pikmin DLC, was nice that they gave you some free each time.

Smash Bros has some great DLC (and some nice free updates as well). Stages and characters are not very cheap but I don't consider them to be heavily overpriced, and I play the game a lot so I don't mind. The Mii costumes however are overpriced and a bit of a rip off. However, its cosmetic only and I don't feel I miss out on anything so it doesn't really bother me.

I also think Nintendoland could have benefitted from DLC to expend upon mario chase, the ghost game, and the animal crossing candy game. Those were actually pretty great but I would have liked more maps and options. Also Mario party 10 could use it, more maps and classic mode please. But it won't happen of course, they'll make Mario Party 11.

I dunno, I bought Yoshi's Wooly World with the little yarn amiibo just so I could have a cuddly little amiibo yarn yoshi, not because IGAF what it unlocked.

I think their DLC okay.. with some being really good and reasonable (MK8) while others, not so much (Awakening, Mario Golf, Smash 4, etc.)

Even with Amiibo, I think it's fine, because they are (generally) compatible with a lot of games.. though supply is really annoying