I just got done watching DS9 for the first time, and frankly I think both shows are on the same level quality-wise. DS9 has some great, great episodes. Off the top of my head, I'll mention ITPL, "Duet," "The Visitor," and definitely a lot more. It had a secondary cast that usually provided some good material in the bad episodes. But it also had a lot of rushed, bad television.
Voyager can be accused of the same (and there are a lot of episodes I won't rewatch), but it also has some great, great episodes. In addition to what exodus
said, I'd add "Counterpoint," which is one of my favorite SeriousTrek episodes of all time, and "Tinker Tenor Doctor Spy," which is one of my favorite comedic ones. I won't talk specifics for fear of spoilering Qutluch
(and I'd kindly ask the rest of you not to as well), but you know what I'm talking about.
Yeah, sometimes they missed the mark, but I find the criticism of Voyager to be really overstated.
For example, it's my crackpot theory that one of the things DS9 was hailed for, "conflict," turns up a lot more on Voyager. Again, not spoiling anything, but especially in the first two seasons there was quite a bit of conflict between main cast members. With all of the Trek shows under my belt, Voyager has more than its fair share of episodes in the rewatch column.