I watch TOS and TAS on a continual basis. Sometimes I'll watch them all, all the way through, by production order. Other times, I watch my favorites, by production order.
I watched about half of season one of TNG when it first was on, but could not take any more of it. Since then, I've seem a few more episodes, such as Unification and Relics - for the obvious reasons.
When DS9 came on, I watched a few, but it never really caught me. However, recently I watched Trials and Tribble-ations when DS9 showed up on Netflix and ended up watching pretty much all of that series. It turns out that I like DS9 better than any of the spin-offs.
When Voyager premiered, I watched just a couple before I realized the error of my ways. By the time Enterprise came along, I knew better (for myself) and have never seen any of that series.