Most of my favourites were on a different medium and at least 50-60 years back. On the television side, that O.J. Simpson commercial sticks in my mind as effective where he is running and jumping through the airport.
all time favourites (high on the list at least): Harlow Wilcox pitching Johnson's Glo Coat or CarNu on Fibber McGee & Molly - such enthusiam and the show never actually stops for the commercial.
or Raymond Edward Johnson pitching Lipton's Tea on the Inner Sanctum. Good samples of both are on my site but not playing attention whore and posting the link in this thread.
another edit: Recent/running ads mostly annoy me or worse, and are good reason for the mute button. Especially that freecredit report spot just mentioned that clearly states enrollment and a monthly fee are required. I heartily recommend
www.mycreditinform.com for credit monitoring purposes.