Clarissa, Hey Dude, and SYS were all fun shows. Simple themes, good characters, and easy to enjoy.

Ted from Hey Dude was featured on the show "Blossom," as Blossom's biyfriend, and tough-guy type, though not bullyish. Melody from the same show is married to Ben Stiller.

Donkeylips from SYS made it onto a few episodes of The Wonder Years.

Al ot of the information on all three shows can be found on Wikipedia.

My favorite way of remembering comes straight from Strong Bad himself:

Oh, if it's supposed to be a possessive, then it's just I-T-S! But if it's supposed to be a contraction, then it's I-T-apostrophe-S! Scalawag!