"The Hardy Boys"
This series [the most well known of all] starred Shaun Cassidy and Parker Stevenson, and was shown on ABC from January 1977 to to January 1979. It alternated with Nancy Drew once a week in the first season. By 1978 the Nancy Drew series was failing. In a last ditch attempt to save the series, ABC combined the Hardys and Nancy for a few episodes. This didn't work and Ms. Drew was canceled in the fall of '78. The Hardys followed this fate early in 1979. 

In the first season (only!), Callie role-played as Fenton's secretary. Chet showed up for one episode and Mrs. Hardy, Iola, Tony, etc., didn't show up at all. Mid-series 1978 brought in two new characters, federal agent Harry Gibbon and CIA operative Harry Hammond. Frank and Joe worked for these men as part of the Justice Department. Oh well, there went all the reality. 
See: Cast  -  Episode List  -  Collectibles 

Joe Hardy: Shaun Cassidy 
Frank Hardy: Parker Stevenson 
Fenton Hardy: Edmund Gilbert 
Callie Shaw: Lisa Eilbacher 
Gertrude Hardy: Edith Atwater 
Harry Gibbon: Phillip R. Allen [third season] 
Harry Hammond: Jack Kelly [third season] 

Nancy Drew Cast [appeared in crossover episodes] 
Nancy Drew (1977): Pamela Sue Martin 
Nancy Drew (1978): Janet Louise Johnson [later known as Janet Julian] 
Carson Drew: William Schallert 
George Fayne: Susan Buckner 
Bess: Ruth Cox 

Episode Guide
Note: Due to space constraints, this is a simple episode list. For a more
detailed episode 'guide,' please click here.
(HB/ND) = Hardy Boys Nancy Drew Crossover Episode
(1/2) = Two-Part Episode
Season 1: 
The Mystery of the Haunted House 
The Mystery of Witches' Hollow 
The Disappearing Floor 
The Flickering Torch Mystery 
The Mystery of the Flying Courier 
Wipe Out 
The Mystery of the Jade Kwan Yin 
Season 2: 
The Hardy Boys and Nancy Drew Meet Dracula (1/2) (HB/ND) 
The Mystery of King Tut's Tomb 
The Mystery of the Hollywood Phantom (1/2) (HB/ND) 
The Mystery of the African Safari 
The Creatures Who Came on Sunday 
The Strange Fate of Flight 608 
Acapulco Spies 
The Silent Scream
Oh Say Can You Sing 
The House on Possessed Hill 
Sole Survivor 
Voodoo Doll (1/2) (HB/ND) 
Mystery on the Avalanche Express (HB/ND) 
Death Surf 
Arson and Old Lace (HB/ND) 
The Campus Terror 

Season 3: 
The Last Kiss of Summer (1/2) 
Assault on the Tower 
Search for Atlantis 
Dangerous Waters 
Scorpion's Sting 
Defection to Paradise (1/2) 
Game Plan 
Life on the Line


Collectibles From The Show
TV Guides - 1978
Canadian Edition (top) and American (below) feature a story on Shaun.
Vanity Fair Record Player - 1978.
Microphone - Now you can sing with Shaun! Dreadful.
1978 - Sun Unlimited Inc.
12.5" Statuette Printed on the pant leg: Shaun Cassidy as Joe Hardy
1978 - Carnival Toys Guitar and Ukelele
1978 - Ideal
"Pocket  Flix" special movie tape.
1978 - Kenner HB Dolls
Comes with various items; guitar, etc.
1978 - Cartoonarama
"Paint Your Own...GREETING CARDS"!
1977 - Vanity Fair AM Radio w/ Mic
Seen in many colours. Box (for a green one) seen below.
Revell Model Van Kit - 1978.
Have your own Hardy Boys Astro!
Parker Brothers "The Secret of Thunder Mountain" Board Game - 1978.
American (left) and Canadian (right; bilingual) versions released.
1977? - Manufacturer unknown; Shaun Cassidy Watch.
MZ Berger also released a Hardy Boys watch in 1978.
1978 - Wonderland Records
Two Hardy Boys Stories, one LP!
A rather silly ordeal, but fairly hard to find.
1977 - King Sealey Lunch Box & Thermos
Fairly cool item for us collectors.
1978 - Vanity Fair
Record Cases; 78 and 45 available.
1978 - American Publishing Corp.
Various HB Puzzles; and some of just Shaun.
1978 - Sun Unlimited
"Love Shaun Cassidy as Joe Hardy" button. Eurgh.
1978 - Collegeville
Creepy-looking Halloween costumes of both Frank and Joe.
Came both hung up and folded in boxes [below].
1970s?...MCA Discovision
Haunted House released in this format.
Don't ask me why.
1978 - Sears
Various Shaun [and on occasion Parker] scenes on jackets, jeans, T-shirts, etc.