Nothing really.

I can't be excited for a logo, but I will be excited for MP4 when we actually see something about it.
I'm not excited for return of Samus, I'll get it someday, but it is so ugly, I'm just like: "meh"
I'm sick of Kirby and Yoshi games, I found them boring, I think the target are little kids and girls, and I'm neither of those demographic.

Now I did got excited for one Switch games revealed during this E3, and that is Mario X rabbids, it looks amazing.

The new ones announced here? Kirby. Technically I'm more excited for Super Mario Odyssey, but that was announced previously, so...

Pokemon, obviously.

Samus Returns. Because it looks great and will be out in three months.

The new Yoshi looks good, but it looks like it will be more Woolly World. Nintendo already has an easy platformer in Kirby. I wish they'd go back to the difficult, and frenetic pace of Yoshi's Island.

Metroid, just because they confirmed a new entry in the Prime series after 10 years.

This...

I'm most excited for Prime 4, considering the brilliance of the series and Tanabe-san's involvement.

Next would be Samus Returns, followed by Kirby.

It's Samus Returns for me, I was so excited when they showed it!

It's kind of unfortunate that so many of the announcements were low key (Pokemon RPG/Prime 4) or for games that are bog standard for their series(Kirby, Yoshi, Metroid 2 Remake).

But the cynic in me cant stop being hyped for so many announcements. Id say Prime 4