W&G
There's a fairly recent episode where Will's dad comes to dinner at Will's place and brings his mistress. At one point around the table, Grace says "Will stop tickling me!", which Will denies. It turns out it was the mistress, thinking she was playing footsies with Will's dad.
Also the one with Shannon Whatshername ("Superstar" girl) who plays a crazywoman. At one point, she and Grace are standing there and she starts tickling her tummy. Grace keeps backing up, but it isn't a ticklish reaction...just a look of terror at realizing this person is insane.
Bandit