I'd say the A&M game was the best/most satisfying. Had totally given up, then the Chamber hit Harper for the long touchdown. Then the OTs, omg.
Texas game was also great. Played horribly offensively and the football wizard Mack Brown still couldn't win. Loved reading national guys reactions all year.
Baylor was definitely the turning point, imo. Agreed on Arthur's INT, the place was rocking, as well as after the 4th down stand. Started to get the feeling "this may be a good year."