I've taken both. Effexor was more effective than SSRI's for me. Some people report horrible withdrawal from Effexor but I had no problems with that. Quite the opposite, I was pretty inconsistent about taking it at the time...

Wellbutrin was the wonder drug that kept me functional for a decade, without mood stabilizers. I still take it but in much lower doses than I used to before I started on Lamictal. The side effects got irritating at the max dose - sweatiness and tinnitus plus some anxiety - but still tolerable. I did have a month of migraines when increasing dose from 300mg to 450mg, but then they faded away.