Out of the listed hash algorithms, Whirlpool is most secure because the other algorithms have been cracked already.

===== WHIRLPOOL: Digest sizes = 512 bits, n 2009, a rebound attack was announced that presents full collisions against 4.5 rounds of Whirlpool in 2120 operations, semi-free-start collisions against 5.5 rounds in 2120 time and semi-free-start near-collisions against 7.5 rounds in 2128 time (https://en.wikipedia.org/wiki/Whirlpool(hashfunction)) ====== ====== RIPEMD: Digest sizes = 128, 160, 256, 320 bits (https://en.wikipedia.org/wiki/RIPEMD). In August 2004, a collision was reported ======
====== SHA0: collisions can be found with complexity 2^61, fewer than the 2^80 for an ideal hash function of the same size (https://en.wikipedia.org/wiki/SHA-1#SHA-0). ====== ====== MD5: Digest sizes = 128 bit, produce a collision for two inputs with specified prefixes within hours, using off-the-shelf computing hardware (complexity 2^39)