I think the better captain of the two is Picard, even though he can be all snooty and stuck-up once in awhile.
Kirk was alright, but he got himself in trouble too many times.
Sub question: TNG has Lt. Cmdr. Data, who can be quite "logical" and Spock-like at times. /ubbthreads/images/graemlins/tongue.gif
Voyager has Cmdr. Tuvok (yes, another "emotion-free" Vulcan), and I'm really not sure who plays that role in DS-9. /ubbthreads/images/graemlins/blush.gif Maybe Odo. /ubbthreads/images/graemlins/smile.gif
The new Enterprise series comes on a channel I don't pick up here, so I don't know who plays the "Spock" role.
Here in Seattle, KCPQ-13 (the only channel I get!) has Voyager on at 11pm and DS-9 on at midnight.