Python 2 or 3?

I'm not sure whether I should focus on learning Python 3.3 or Python 2.7. What's your opinion on the matter?
(I don't want Andru's advice)

>>18
Ruby is the best one of them but it's also generally slightly slower no matter what the VM it runs on. If a small performance gain is more important than the programmer's pleasure and productivity, then choose Python.
And Perl is an old piece of garbage that the Perl guys unsuccessfully try to revive by adding more bloat and incomprehensible garbage.