I suppose it depends on the levels you have personally.
If you find your depressive state of bipolar is worse than your manic state, it may be best to try to level out the depression. Whereas, if you're main problem is the Mania, that'd be the best one to eliminate.

Personally, I can't cope with either - depressive or manic, but if i had to choose, i'd say i find my manic state easier to deal with. But that may be because i don't seem to experience the mania quite as much as the depression, so it's over before it can start getting to me too much. a week or two of mania is nothing compared to months of depression.

*Shrugs* there are many opinions towards it. It depends on your ability to cope with each.

Kelly. x