Another good question. We address this a lot in our new book, Sous Vide: Help for the Busy Cook
, which is all about getting meals on the table quickly during a busy week.
In general though we suggest trying to find cuts of meat that need the extra cooking time such as rib roasts, flank steak, sirloin steak, etc. You wouldn't want to cook tenderloin for 8 to 10 hours as it would start to get too tender.
We also experimented with chicken breasts and while it's a longer time than usually recommended, even after 12 hours they are still pretty good, especially for a weekday meal.
And fish would definitely not do well in the water bath for 8 hours, it would probably turn into mush.
I hope this helps some!