Next Gen used to be on around bedtime. It became a go-to. I also enjoy DS9 and Voyager, but not quite as much as Next Gen. I simply couldn't get into Enterprise because the captain could never be anything but Quantum Leap guy to me!
It's rather hard for me to choose, as i grew up watching the original as well as Next Generation, but when recently watching the show again i started with Deep Space Nine and some of the episode themes really hit home with me and made me fall in love with that season.