Ah yes, I have been on all three.
OK, abilify and geodon are pretty similar as far as what they are intended for. Lamictal is a different story. Abilify and Geodon are primarily antipsychotics, but people have been using them for mood stabilization lately. They are good if you have a lot of psychotic manias because they help with psychoses as well.
Lamictal, on the other hand (the only one of those three that I'm still on), is primarily a mood stabilizer and also has some anti-depressant qualities. From what I understand, it is generally the choice mood stabilizer for people who are predominantly depressed.
I don't remember especially severe side effects on either abilify or geodon, but I do know that Lamictal makes me extremely constipated, so I take stool softeners daily which counter that side effect nicely.
I hope that helps, and good luck!