I did a quick scan of the rest of this forum and couldn't see anything obvious, so I'm starting this thread 
Because of Voyager's nature of travelling through the Delta Quadrant, they came across a few recurring enemies, and as they left their space, they came across new ones.
Which was your favourite or least favourite? Which one was the biggest missed opportunity or which one was done to death?
Just a quick list of the ones I can think of offhand:
Kazon
Vidiians
Borg
Species 8472
Hirogen
Malon
Vaadwaur
Hierarchy
I always liked the Vidiians and the Hirogen. There were signs of a deeper culture to be explored, and both were horrific and needed to be feared for their own reasons. Neither were bound by honour, or ethics as such, and this gave them the edge that lot of other races don't always have.
The Kazon and Malon... while they take a lot of criticism, I think they were okay, but didn't really get the development they deserved, and so, I was never really convinced they posed a real threat (despite the Kazon actually crippling Voyager, boarding her and even stealing her at one point).
The Borg were way overused, to the point where I just didn't care, nor fear them by the time of Unimatrix Zero. Janeway starts picking fights with them in Dark Frontier, and then she is even willingly assimilated in Unimatrix Zero. Assimilation is the most horrific thing Trek ever gave us - the loss of your own self, and it became a case of "oh well, I'll do it because the Doctor can take out all the implants later".
8472 were intriguing, especially after Prey, and the fact that they fear the humans enough to try and act like them to infiltrate and destroy them. Janeway makes a speech and you never see them again which is a shame.
The Hierarchy were good, but they were only used for comic relief, and so they don't rate very highly with me.
And finally, the Vaadwaur. Voyager unwittingly lets loose the race that once owned the Delta Quadrant and opens Pandora's Box. They even threaten that they've not seen the last of them. And except for a brief glimpse in The Void, they're never mentioned again. It was a massive wasted opportunity and I feel hurt the series in its last two seasons as there was definite arc potential.
So that's my two pennies... I would've liked some more Vidiian and Hirogen stories, but I'm fairly happy with what we got. What about you?

Because of Voyager's nature of travelling through the Delta Quadrant, they came across a few recurring enemies, and as they left their space, they came across new ones.
Which was your favourite or least favourite? Which one was the biggest missed opportunity or which one was done to death?
Just a quick list of the ones I can think of offhand:
Kazon
Vidiians
Borg
Species 8472
Hirogen
Malon
Vaadwaur
Hierarchy
I always liked the Vidiians and the Hirogen. There were signs of a deeper culture to be explored, and both were horrific and needed to be feared for their own reasons. Neither were bound by honour, or ethics as such, and this gave them the edge that lot of other races don't always have.
The Kazon and Malon... while they take a lot of criticism, I think they were okay, but didn't really get the development they deserved, and so, I was never really convinced they posed a real threat (despite the Kazon actually crippling Voyager, boarding her and even stealing her at one point).
The Borg were way overused, to the point where I just didn't care, nor fear them by the time of Unimatrix Zero. Janeway starts picking fights with them in Dark Frontier, and then she is even willingly assimilated in Unimatrix Zero. Assimilation is the most horrific thing Trek ever gave us - the loss of your own self, and it became a case of "oh well, I'll do it because the Doctor can take out all the implants later".
8472 were intriguing, especially after Prey, and the fact that they fear the humans enough to try and act like them to infiltrate and destroy them. Janeway makes a speech and you never see them again which is a shame.
The Hierarchy were good, but they were only used for comic relief, and so they don't rate very highly with me.
And finally, the Vaadwaur. Voyager unwittingly lets loose the race that once owned the Delta Quadrant and opens Pandora's Box. They even threaten that they've not seen the last of them. And except for a brief glimpse in The Void, they're never mentioned again. It was a massive wasted opportunity and I feel hurt the series in its last two seasons as there was definite arc potential.
So that's my two pennies... I would've liked some more Vidiian and Hirogen stories, but I'm fairly happy with what we got. What about you?