Bruce Willis did not receive an Oscar nomination for portraying Butch Coolidge in Pulp Fiction.
Butch is probably one of the least talkative characters in the film, and unlike most of the characters who like their long speeches Butch though mostly reacts to someone else talking, and is much more a man of actions rather than words. Willis was the right choice in the role as he often plays a man of action and is able to portray such a role with a fair amount of ease. Willis being a competent action hero if very good in conveying the emotions of a character while the character is on the move. This works particularly well for Butch in the opening of his story as Willis tells a great deal about him just as Butch escapes the Boxing arena and takes a cab to escape. The film does not dwell on the emotions but Willis gets across the desperation and determination of Butch instantly.
Butch honestly does not have the flamboyancy or the complexity of the characters of Jules (Samuel L. Jackson) and Vincent Vega (John Travolta). His role is very much different in that he is very much the more traditional lead. His most defining features are that he does things his own way as well as that he very much respects his watch that has been handed down in his family. There is not a great deal more to him than that, and that really is plenty for Willis to make him the compelling enough character for his story. The middle story actually has considerably more actions scenes than the other stories, and Willis traverses these well always being believable through any of the situations that Butch finds himself in.
Willis is continues to be effective throughout his story just a very much average hero going through the story and delivers in his scenes whether they need a strong presence, some emotional weight, or a little bit humor. Willis brings all of these qualities naturally to the part of Butch, and leads his story just as he should in his usual leading man way although in this case in a much smaller scale. I would say this is not the best performance by Willis in this style, nor would I say he is the most memorable part of this film. This is a fine example of Willis's strength as a performer though, and realizes the character of Butch properly.