In my opinion, Voyager's greatest (?!) contribution was in poorly written stories that took Star Trek far enough off the rails that no more really good Trek could be made without a semi-reboot of the franchise. Which resulted in the excellent movie earlier this year.
So, um, right on, Voyager! Yeah....
I did kinda like the Voth, Species 8472 (before the writers immediately turned around and neutered them), the concept
of the EMH, and the design of the Delta Flyer.