Zoloft made me have 5 hour blackouts, most of the time I was riding the Metro / driving in DC area when that happened. I didn't realize it until I was coming out of work one day on the 3rd story in the Pentagon City Mall, and ended up on the bottom of the metro stairs with a sprained ankle, bruise the size of a softball on my head, and scratches up and down my arms from tumbling down more than one escalator.
Wellbutrin isn't as bad, but the sexual side effect is insane for me... (ie: zero to nympho. Seriously. almost no sex drive without it, and wanting to hump everything on it...

) Unlike someone previously mentioned though, my withdrawal is almost as bad as heroin though, so I tend to stay at a very low dose.