It's probably a bit late for this, and it might not even matter to people, but I did it out of curiosity anyway.
I've calculated which play style gives you the most adam, assuming:
-The presents that you get from the little sisters contain 80 adam.
-You gather adam with every little sister.
There are 12 little sisters in the game. You get a present after saving 4 L.S.. A normal gathering gives you 80 adam (2 bodies). You receive the "Proud Parent" tonic after saving 4 L.S., which gives you 60 adam per body gathered (normal gathering now is 120 adam). I'm also not counting Big Sisters and any other miscellaneous adam you can get.
If you save all of the L.S.:
If you harvest all of the L.S.:
If you abuse the "Proud Parent" tonic and still harvest the L.S.
I was actually surprised by the results. Harvesting them all may not be the most profitable in the long run, but it gives you a shitload of adam to spend short term. And of course, saving the little sisters sucks dick if you want great plasmids early.