Joe Isuzu commercials were great. Wendy's had some doozies, as did ESPN with the Sports Center/nascar ride-alongs.
I don't have any TV services, so I don't see much, but I have chuckled at the geico ones.

Years back there was some that had the Frazier guy voicing a ream of paper, but I can't remember what the product was. They were OK

Typical Wendys: