Tough question....
I'll echo the sentiments of others here and throw Oliver and Cox into the mix.
For some reason - I never really understood why, other than that he was a Dolphin - I hated Keith "Fatass" Byars.
I'll have to go with Marino, though. He was a whining POS, but I thank for him losing virtually every big game he played against the Kelly-led Bills. On a side note, I ran into him at a bar back during his playing days, and I told him that he and the Dolphins sucked. He walked away.