I don't think Wooten, Les or Flea could hold a candle next to Cliff, but other than that pretty much agree. I play a little bass, that's why I asked. It didn't occur to me that people who aren't pretty familiar with it, wouldn't be interested, but it makes sense. Maybe more people would be interested in guitarists, should I give that a try?
I think Cliff is a lock as #1. I would say Ellefson is the only guy that comes close to him. The others are tougher to decide, for a lot of reasons, mainly because bass isn't seen as a necessity in thrash and a lot of them didn't get many chances to show what they could do. Still, I think most of them are pretty good bassists.