I might have to disagree a bit with Elk Grove, you see all of the famillies moved down there, as the kids get older crime is going to increase and will get pretty wild, I think thats already starting to happen.
Personally I would take Highway 50 over 80 ANY day of the week. I find it very odd 80 is backed up in Roseville on the weekends. Roseville is nice, but everyone and their mother lives up there and is a mini malll/cookie cutter subdivision nightmare.
Folsom is nicer IMO, but is just like Roseville in some areas...little older and has some more character with the history.
Depending on your age or what you are exactly looking for, ie: proximity to the nightlife or quiet. Answers will vary.
If I had my choice I would like a place on Highway 16 just outside of Sac on some property, say near the Sac Drag Strip which is just outside of town but close enough. Or on American River drive/Fair Oaks, which is still in town.
However, doesn't really matter going to cost an arm or a leg anywhere you are it seems in CA nowadays.