The first looks like it might be 'Bleach', but I am not 100% sure on that. (I gave up being an otaku when my son was born. Now I just 'consult' on my nephew's and niece's purchases).

Make sure they enter in the Anime News Network Pumpkin Carving Contest.

Maybe that first one is Ghost Rider?

Nope, Definatly the Bleach Skull.

Second one looks like the symbol for the village of the hidden mist in Naruto.
Link to a village guide: http://www.narutofob.com/naruto-villages.html

While naruto is on cartoon network in the states, it is a few years behind the japanese version.
You can find subtitled versions of the original japanese ones on dattebayo.com.
The manga itself upon which the anime is based is even further along in the story line.
For those you can check narutofan.com.

Fail, guys. It's the Gurren Brigade Emblem from Tengen Toppa Gurren Lagann.

Good guess with bleach though.

"Who the hell do you think we are?"

I guess not anime watchers... It is Gurren Lagann, just look at the sunglasses it has...

Gurren Lagann one looks off the hook. Need to try that myself somtime. Although the bleach guess was pretty good.