When speaking about speed decks, the most important question is:
unupped? fully-upped? for a begginer/newbie? for an experienced player?
For example rainbow golem rush is very fast even unupgraded, but it's quite expensive to make (6 immolations) no matter what starting deck you take.
Life rush might be the easiest to use for a newbie, a shrieker rush requires a little bit of strategy sometimes (when to evolve all graboids at once, whether to burrow them etc.) which might be better to teach a newbie some timing and counter-creature control.
I guess speed decks that work against top50 are better than those that work good only against AI3, as newbies need rares.
Anyway, my vote goes for graboid rush simply because it has a
![Time :time](https://elementscommunity.org/forum/Smileys/solosmileys/../../../images/Misc/time18x18.png)
mark
![Tongue :P](https://elementscommunity.org/forum/Smileys/solosmileys/tongue.gif)