The CA i prefer has just been discovered[1] (by myself while exploring B0 rules), and has two variants, both of which are shown to the right.
It is originally called "SlowLife", but because that name is taken, it is now called either "SlowLifeB0", "New SlowLife", "Sl0wlife", or any other you like as long as it does not differ too much from "SlowLife".
Both variants are not yet proven Turing-complete, but it'll be appreciated if you help to prove it Turing-complete.
I also like a few other CA, as documented in this thread[2], which is actually kind of a poll ( User:Iddi01/Most_popular_OCA )
Interesting stuff discovered
I've discovered a few interesting, but still un-noteworthy CA. Here's one of the best: