Here's the link
I don't know exactly why, but I think my all-time favorite is Jason Sehorn's interception of Donovan Mcnabb. Something about the combination of unbelievable athleticism and it being, well, against the beagles!
I usually just vote for all of the Giants plays and against all of the Eagles and Cowboys plays in these nfl.com polls. Stupid, Yes. But I'm not sure I could live with myself if I helped another NFC east team win best play of all time.