Halloween cubees

If you're new to papercraft, then cubees are definitely a great start.
This set of cubee halloween crafts are easy to make, yet look striking when completed
Grab them here:

http://paperkraft.blogspot.com/2009/10/halloween-cubee-paper-toys-monsters.html
(paperkraft.net)

Gundam beam rifle

a rifle used by Mobile Suit RX-78-2
I haven't gotten around to making this one myself, but it looks pretty challenging.

http://paperkraft.blogspot.com/2009/11/gundam-beam-rifle-papercraft-rx-78-2.html

The invincible iron man

This easy, yet detailed iron man model has a removable chest plate and helmet.

http://paperkraft.blogspot.com/2009/11/invincible-iron-man-papercraft.html (paperkraft.net)