Drop down terminal as smooth as gnome-shell's 'looking glass'

There's a new GNOME Shell extension that makes exactly what you need!

It's called Drop Down Terminal. It's compatible with GNOME Shell 3.6 (and older versions as far as I know).

Go with Guake terminal. It's easy to customize, and works like a charm.

Look for it in the Software Centre.

Try Tilda, even though all the features aren't enabled out of the box, the preference editor lets you adjust everything easily, you can adjust the animation speed rates, width, size, fading, etc.

EDIT: Also, it only blinks if you don't have compositing enabled system-wide. It runs as a background process underneath EVERYTHING even TTY's