A lot of people come into the no-kill shelter where I work asking for my opinion on this topic. I always tell them that either way they are saving a life because if they adopt from us, it opens up a cage for us to fill when we go over and rescue animals from the kill shelter or when we take in an animal that might have otherwise been dumped in a not so nice place.
I think as far as donating money, it is better used at a no-kill shelter, at least in my town. The kill shelter here is city funded and my no-kill shelter is a non-profit charity. Unfortunately, the city shelter has so many animals, that they just don't give them the care that we give our animals. They provide the very raw, basic needs: food, water, shelter. Dogs and cats need much more than that. They need soft bedding, attention, and mental stimulation. I have no clue what the kill shelter here does with their donations because I never see toys or beds in those cages. It is really sad. Our donations go directly toward the physical and mental care of our animals.
And as far as volunteering, I think if you are strong enough emotionally, a kill shelter might need volunteers more. The kill shelter here has city employees working there. They are disgruntled and don't care about the animals. Those animals deserve to have some care and know what love is, even if it is just for a few short minutes before their lives are taken.
But whether adopting, donating, or volunteering, ANY shelter will much appreciate the help. I used to have the mindframe that I WOULD NOT ever support a kill shelter financially or otherwise, but I now realize that they don't really have a choice. The blame really points to all those stupid people that dump animals on the roads, let their animals have babies, don't understand animals are a lifetime committment, etc etc.
Enough rambling from me
Shiloh, Reece, Lolly, Skylar
and fosters Snickers, Missy, Magic, Merlin, Maya