Season 6 (according to the CTW Archives):
667. David Is Too Tired To Take Care Of Hooper's Store. 11/5/74
668. Oscar Is Delighted By The Rainy Day Outside. 11/6/74
669. Sam The Robot Tries To Act Like A Grandmother. 11/7/74
670. Big Bird Tries To Leave A Trail Of Bread Crumbs. 11/8/74
671. Oscar Invites Bob Into His Trash Can. 11/11/74
672. Ernie And Bert Get Mad At Each Other. 11/12/74
673. Big Bird Writes A Love Note To Maria. 11/13/74
674. Mumford Decides He's All Washed Up As A Magician. 11/14/74
675. The Count Helps Big Bird Write A Poem. 11/15/74
676. Big Bird Imagines He's Living 100 Years Ago. 11/18/74
677. Oscar Is Afraid Of Thunder. 11/19/74
678. Sam The Robot Confuses Everyone By Imitating Sounds. 11/20/74
679. The Count Counts Things In Oscar's Trash Can. 11/21/74
680. Biff And Sully Repair Underground Pipes. 11/22/74
681. The Count Helps Luis By Putting Nails And Screws Away. 11/25/74
682. Big Bird Helps David To Keep From Falling Asleep. 11/26/74
683. Oscar Impersonates Other People To Avoid Being Bothered. 11/27/74
684. Cookie Monster Becomes A Cookie Watcher. 11/28/74
685. Oscar Disagrees With Luis's Decisions As An Umpire. 11/29/74
686. Oscar Plants A Tree In Front Of His Trash Can. 12/2/74
687. Linda And The Theater Of Deaf Put On A Show. 12/3/74
688. Sam The Robot Plays A Game With Oscar. 12/4/74
689. Oscar Sets Off An Explosion In His Trash Can. 12/5/74
690. Maria Hits Her Finger With A Hammer. 12/6/74
691. Maria Imagines That She's A Bus Driver. 12/9/74
692. Oscar Expects A Group Of Grouches From Cincinatti. 12/10/74
693. Bert Loses His Favorite Bottlecap. 12/11/74
694. Biff And Sully Share A Soda. 12/12/74
695. Oscar Opens A Break-It Shop. 12/13/74
696. Oscar Reprograms Sam The Robot. 12/16/74
697. Big Bird, Gordon, And The Kids Play In A Cold Playground. 12/17/74
698. Oscar Becomes A Doctor, A Conductor, And A Librarian. 12/18/74
699. Oscar Makes A Mess Of The Newspapers. 12/19/74
700. Maria Borrows A Cup Of Sugar From Oscar's Kitchen. 12/20/74
701. David Sells Sets Of Books About 4 And Q. 12/23/74
702. Maria Gets A Job As A Construction Worker. 12/24/74
703. Big Bird Builds An Airplane. 12/25/74
704. Oscar Plays A Trumpet. 12/26/74
705. Grover Recycles Newspapers And Magazines. 12/27/74
706. David Tries To Learn Spanish. 12/30/74
707. Oscar Hates His Alarm Clock. 12/31/74
708. Snuffy Loses Every Game That He Plays With Big Bird. 1/1/75
709. Herry Makes A Mess Of Hooper's Store. 1/2/75
710. Oscar Opens A Grouch School. 1/3/75
711. Sam The Robot Celebrates The Day He Was Wired. 1/6/75
712. Grover Wants To Visit With People. 1/7/75
713. Big Bird Gives Everyone Gifts. 1/8/75
714. Oscar Plays Horrible Noises On His Tape Recorder. 1/9/75
715. The Count Threatens To Give Up Counting. 1/10/75
716. The Count Has A New Vehicle, The Countmobile. 1/13/75
717. Big Bird Tries To Make Sure He Gets A Good Night's Sleep. 1/14/75
718. The Count Helps Out At Hooper's Store. 1/15/75
719. Reverend Kirkpatrick And Ed Lipton Visit. 1/16/75
720. Muppets Express Themselves Using Pencils. 1/17/75
721. The Count Looks For A Job. 1/20/75
722. Oscar Buys Paintings At The Grouch Fair. 1/21/75
723. Bad Barney Blackmails Big Bird. 1/22/75
724. Big Bird Wants To Send Flowers To Susan's Sick Mother. 1/23/75
725. David Leaves Cookie Monster In Charge Of Hooper's Store. 1/24/75
726. Big Bird Makes Birdseed Cookies. 1/27/75
727. Big Bird Babysits An Egg Which Hatches. 1/28/75
728. Bob And Big Bird Discuss Which Is Better To Have, A Beak Or A Nose. 1/29/75
729. Snuffy Practices Feelings. 1/30/75
730. Sam the Robot Demonstrates Some And More. 1/31/75
731. Oscar Pretends To Be A Pirate. 2/3/75
732. A Prince Visits The Street To Rescue A Lady In Distress. 2/4/75
733. The Count Promises Luis That He Won't Count For The Whole Day. 2/5/75
734. The Number Four Show. 2/6/75
735. The Count Cries When There's Nothing To Count. 2/7/75
736. Herry Gets A Box Of Bricks As A Present. 2/10/75
737. Oscar Helps David Talk About The Letter N. 2/11/75
738. The Count Visits Hooper's Store To Find Something To Count. 2/12/75
739. Herry Shows Off How Strong He Is. 2/13/75
740. Big Bird Tries To Prove He's Old Enough To Do Anything. 2/14/75
741. Pete Seeger Visits Again. 2/17/75
742. Cookie Monster Tries To Find A Cookie Blindfolded. 2/18/75
743. Oscar Calls The Grouch Market. 2/19/75
744. The Count Follows An Ant. 2/20/75
745. Big Bird's Cousin Herman Visits. 2/21/75
746. Snuffy Tries To Introduce Himself To Mr. Hooper. 2/24/75
747. Big Bird Wants To Learn About Clocks. 2/25/75
748. Oscar Sings "Swamp Mushy Muddy". 2/26/75
749. Oscar Has A Symphony Orchestra In His Trash Can. 2/27/75
750. Oscar Doesn't Want David To Become A Lawyer. 2/28/75
751. The Count Celebrates National Counting Day. 3/3/75
752. Sam The Robot Tries To Play Music For David. 3/4/75
753. Biff And Sully Tries To Move Susan's Piano. 3/5/75
754. Oscar Makes Believe That He Has Duck Pox. 3/6/75
755. Oscar Pretends That It's Night. 3/7/75
756. Oscar Moves Away From 123 Sesame Street. 3/10/75
757. Big Bird Teaches Grover About Eggs. 3/11/75
758. Big Bird Is Offended By Simon Soundman. 3/12/75
759. The Count Wants To Stay Awake At Night And Count Stars. 3/13/75
760. Herry Joins In A Game Of Kick The Can. 3/14/75
761. Big Bird Is Locked In Hooper's Store. 3/17/75
762. Gordon Helps Big Bird Thing Of L Words. 3/18/75
763. Jose Feliciano Visits. 3/19/75
764. Big Bird Goes To The Store For Milk And Birdseed. 3/20/75
765. Herry Gets Mad At Luis And Susan. 3/21/75
766. Snuffy Drinks David's Bucket Of Water. 3/24/75
767. Luis Makes A Phone Call With Sam The Robot. 3/25/75
768. Snuffy Brings A Snuffy-Sized Trash Can. 3/26/75
769. Snuffy Drinks Soapy Water From A Bucket. 3/27/75
770. Maria And Big Bird Play A Rhyming Game. 3/28/75
771. Oscar Warns Everyone That It's Going To Rain. 3/31/75
772. Big Bird Makes His Own Drum. 4/1/75
773. Sam The Robot Makes Lunch. 4/2/75
774. Bird Bird Offer's To Be Luis's Songbird. 4/3/75
775. Sam The Robot Tries To Make A Handball. 4/4/75
776. Luis, Susan, And The Kids Cooperate To Clean The Street. 4/7/75
777. Susan Tests Big Bird's Memory. 4/8/75
778. Cookie Monster Tries To Trick David For A Box Of Cookies. 4/9/75
779. Oscar Gets His Job As A Dishwasher. 4/10/75
780. Oscar Invents A Noise Machine. 4/11/75
781. Oscar Is Tired Of People Dumping Garbage In His Can. 4/14/75
782. Luis Buys A New Hat. 4/15/75
783. Oscar Wins The Grouch Of The Year Award. 4/16/75
784. Big Bird Redecorates Hooper's Store To Give It Bird Appeal. 4/17/75
785. Big Bird Pretends To Be A Woodpecker. 4/18/75
786. Mr. Hooper Loses His Glasses. 4/21/75
787. Oscar Builds A Hatrack. 4/22/75
788. Maria And David Play Ping-Pong. 4/23/75
789. David Tries To Study For A Law School Exam. 4/23/75
791. Mr. Hooper Finds Snuffy's Postcard. 4/27/75
792. Oscar Conducts The Grouch Philharmonic Orchestra. 4/28/75
793. Slimey The Worm Has Disappeared. 4/29/75
794. Ernie And Bert Decide To Go Their Seperate Ways. 4/30/75
795. The Count Counts Water Drops And Leaves. 5/1/75