Robert Mitchum?
I love "Big Bob" and he did fine work as Pug but I read Herman Wouk's novels before the mini-series was made and while I was reading I could only picture Glenn Ford as Pug Henry. It took quite a few episodes before I got used to Mitchum, and as you can tell it's 2005 and I still haven't gotten over it.
Anyone else do pre-casting while they read and how did you feel about the actors (that is, besides prefering Seymour and Bochner to McGraw and Vincent)?