Officially
DA 18-55 AL
DA 18-55 AL
II; optically improved version of above
DA 18-55 AL WR; WR version of the II
And there is the DA-L 18-55 (maybe with AL at the end but I have not seen one so don't know), the el cheapo kit lens for the K-x/K-r; missing lens hood is the biggest difference with the above. Also has no quickshift, no distance scale and has a plastic mount instead of a metal mount.
The II, WR and DA-L are optically the same (from hear say). And I would get one of those.
PS The only stupid question is a question not asked