I've been on the hunt for the following episodes for these sitcoms:

Head of the Class:

Season 2: Love is Debatable and We Love You, Mrs. Russell
Season 3/4/5: Any episodes (I have The Refrigerator of Fillmore High, Back in the USSR, Mission to Moscow Part 1 and 2, Let's Rap, Engen and Son, Born to Run, Get a Job, First Date, Partners, Viki & Eric & Simone & Alex, Viki's Torn Genes)

The Hogan Family/Valerie/Valerie's Family: Any Original NBC/CBS recordings

It's a Living:

Just looking for the one missing episode from my collection: Season 4 episode: Bachelor Party.

9 to 5:

Any episodes from Season 2-5

One Day at a Time:

Season 6: Ann Meets Nick: Part 1, and It's All in the Cards

Season 7: Alex's First Love, Meow, Meow, Ann's Failure, Grandma's Nest Egg, Hear Today, Gone Tomorrow, Auntie Francine, Catcher in the Mud

Season 8: Last Time I Saw Paris, A Young Man's Fancy, Sonny Boy, The Letter

Season 9: The Bedtime Story, The Dentist, Shakedown, Worried Heart, Sam's Apartment, Up in Smoke, Meaning of Life, Parting Company, Fifty, Ave Romano

227:

Season 5 episode: Nightmare on 227

If anyone has any of these episodes and would be able to help me out, please let me know. I would totally be up from some trading. Respond to this post or IM me. I can get you my trade list.