How to Bed Level?

I've got my Kossel up and running, but I still haven't gotten my bed quite level yet. I've got the printing flattened (no noticeably concave/convex curve) but my G29 autoprobe results show a slant on my bed. Is there anything else I can look at for leveling, or is G29 the end-all and be-all of bed leveling?

my probe doesn't push itself back up at the end of the probing, so I cant really use that when printing right now...

any help would be appreciated!