No sooner had Samantha been named Best in Show by the Westminster Kennel Club on Tuesday night than she started enjoying her 15 minutes of fame. Yesterday the English springer spaniel kicked off her day with a 5:30 a.m. wake-up call in her midtown Manhattan hotel. (She reportedly had been out late partying the night before.) She was due at ABC’s “Good Morning America,” where she ultimately won over cohost Charlie Gibson. It was then off to NBC’s “Later Today,” where the 5-year-old appeared with interviewer Jodi Applegate. When Applegate inquired of the champ’s owners, Carl Blain and Fran Sunseri, about Samantha’s temperament, the two humans did not have a chance to answer. Samantha was already licking Applegate’s face.