You can get a Large Blue Dragon in the current edition of the Basic Game.
Otherwise:
* Large Black Dragon - likely in Unhallowed
* Huge Black Dragon - in War of the Dragon Queen, being ridden by sorcerer.
* Large Blue Dragon - Basic Game & Deathknell
* Huge Blue Dragon - none
* Large Green Dragon - War Drums
* Huge Green Dragon - none
* Large Red Dragon - Dragoneye
* Huge Red Dragon - Giants of Legend
* Large White Dragon - none (zombie in Deathknell)
* Huge White Dragon - none
Cheers!
