Bougainvillaea - I have two in pots hanging from either end of my swing frame in the backyard. The thorns are certainly a deterrent for animals and birds, alike.
First picture is from September - when all was still green - I was trying to capture a few hummingbirds....
http://i228.photobucket.com/albums/ee260/TxChiknRanchers/bougainvillaea.jpg
I took this picture today - rainy, cold, miserably wet day - but flowers are still beautiful even though the leaves are getting bare.
http://i228.photobucket.com/albums/ee260/TxChiknRanchers/bougainvillaea2.jpg
I plan to remove them from the pots in the spring and plant them at the front of the driveway on entry posts that my wonderful DH is going to build for me
I also have jasmine - makes beautiful yellow, fragrant flowers. However, I think animals love it - I know the chickens do!