I was, for collection but some of the production pieces are so underwhelming compared to the prototype.

Probably not for each game that supports amiibo, but there will be different lines of amiibo made for different games, with different functionality. At least, that's how I understood their explanations of amiibo.

I am more interested in the potential than in what was annouced so far. Only they being Smash sparring partners is kinda cool.

I'm less excited by the amiibo functionality itself than I am by what it's likely to mean.

Specifically, games being updated with more content in one way or another. For example, consider Hyrule Warriors. In addition to all of the great DLC already on the way/already here, it's been confirmed that Link's amiibo will unlock a new weapon in the game. And Zelda will, too... although it's not yet clear whether it's a different weapon, or just the same weapon for Link with a different amiibo.

Now consider that Toon Link will undoubtedly also get an amiibo. We could very well get another weapon inspired by Toon Link (Spinner is inspired by TP Link, which is the Link that the Smash 4 Link is based on, after all). And Sheik and Ganondorf, too (both of which currently only have one weapon type in the game). And it's possible that alternate versions of the amiibos in card form will be cheaper while still enabling much of the same content... or they could open the functionality up to direct eShop purchase for those who don't want to buy the amiibo.

All that extra content is a possibility, and probably wouldn't happen if not for amiibos. And this is likely to happen across a variety of games. I'd expect most Amiibos to have costumes for Mario Kart 8 (and if they're updating the game with that sort of content, maybe they'll also add other stuff). I'm betting that Captain Toad will get amiibo stages (levels unlocked by the amiibo, inspired by the respective character).

And that's what I'm excited for - because if they're going to keep updating games with more amiibo functionality, they might as well also add other stuff along the way.

I'm also excited that Link seems to be the best choice of amiibo for unlocking substantial things, so far, since it's the one I was planning on buying.

3 games is now almost every game that comes out?

I count 5, and Hyrule Warriors is not included there.