Mystery House (1980, On-Line Systems).  Written in 1979, this game was the success story which established Ken & Roberta Williams as major software developers.  It was written for the Apple II, and is known in gaming circles as the first graphic adventure game, although the graphics were simply black & white drawings to help the game's players to visualize the action.  It was re-released in 1982 under the SierraVenture logo.  Finding this game is an adventure in itself!  However, it was included in The Roberta Williams Anthology, along with many other classics.

The Wizard and The Princess (1980, On-Line Systems). Released for the Apple II, Atari ST and C64 personal computer systems, this game is regarded as the first graphic adventure game in COLOR.  It too was re-released in 1982 (IBM PC only) under the SierraVenture logo, but the name was changed to Adventure in Serenia.

Mission: Asteroid (1980, On-Line Systems).  Released for the Apple II personal computer system, this game was billed as a "tutorial adventure", designed to teach players how to play a graphic adventure.  After all, the concept was a new one!  It was re-released in 1982 under the SierraVenture label, and then again in 1983 for the Commodore 64. 

Cranston Manor (1981, On-Line Systems).  Another innovation for Sierra, this game allowed the player to switch between TEXT and GRAPHIC modes, as well as permitting the player to insert a disk and save their progress.

Crossfire (1981, On-Line Systems). An arcade game first released for the Apple II, then re-released under the SierraVision label in 1982 for the Commodore VIC-20 and IBM PC.

Frogger (1981, On-Line Systems).  Another arcade game classic, originally released for the Atari 400/800, this game was re-released under the SierraVision label in 1982 for the IBM PC and Commodore VIC-20.

Jawbreaker (1981, On-Line Systems).  Another arcade game for the Atari 400/800, and another game re-released in 1982 under the SierraVision label for the IBM PC and Commodore VIC-20.

Mouskattack (1981, On-Line Systems).  First published for the Apple II in 1981 by On-Line Systems, this arcade game was re-released in 1982 under the SierraVision label for the Atari 400/800, and the IBM PC.

Threshold (1981, On-Line Systems).  An arcade game released for the Apple II computer under the On-Line Systems label, and re-released for the IBM PC and Commodore VIC-20 in 1982.

Soft Porn Adventure (1981, On-Line Systems). By Chuck Benton, this game is notable for being the only text adventure (no graphics!) ever released by Sierra in any of its incarnations.  It is also the precursor of the popular Leisure Suit Larry series, and can be found on the Leisure Suit Larry Collector's Edition.

Thrilogy (1981). A combination of Break Out, Head On, and a game based on William Tell, published for the Apple II computer.

Time Zone (1981, On-Line Systems).  Easily one of the biggest games of its time, this monster came on six (!) floppy discs and retailed for $99.95.  Released for the Apple II and IBM PC, the price tag was simply to high for the buying public, and the game sold poorly.

Ulysses and the Golden Fleece (1981, On-Line Systems).  Originally released for the Apple II and Atari 400/800 computer systems, this game was re-released in 1982 under the SierraVenture label and again in 1984 for the Commodore 64.

Ultima I (1981, SierraVenture).  Before there was an ORIGIN Systems, Inc., Richard Garriot formed the California Pacific Company published the very first Ultima in 1980 for the Apple II.  The company folded, and he sold the publishing rights to both Ultima and the then unreleased Ultima II to Sierra.  Sierra released Ultima for the Atari 400/800 under the SierraVenture label.

Laff Pak (1982)  For Apple II. Designed by Chuck "Chuckles" Bueche (co-founder of ORIGIN).

Lunar Leeper (1982, SierraVision).  Another arcade game, created by Chuckles, and released for the Commodore VIC-20, Commodore 64, Atari 400/800, and Apple II platforms.

The Artist (1982).  For Apple II.

The Dark Crystal (1982, SierraVenture).  Another Sierra first!  This game was the first movie tie-in game for Sierra (based on the Jim Henson movie of the same name) as well as the first game to be published under the SierraVenture label.  It was originally released for the Apple II and Atari 400/800 computer systems, and would see a re-release under a different name in 1984.

Ultima II: The Revenge of the Enchantress (1982, SierraVenture).  Sierra published Richard Garriot's second Ultima game on both the Apple II in 1982.  They followed up with Atari 400/800, Commodore 64, and IBM PC versions in 1983.  In 1984 a grey box version was produced for the Apple II and Atari ST, followed in 1985 by a grey box version for the Commodore 64 and the Macintosh computer platforms. 

Apple Cider Spider (1983, SierraVision).  An arcade game released for the Apple II in 1983 and again for the Commodore 64 in  1984.

Aquatron (1983, SierraVision).  Air/Sea battle arcade game for the Atari 400/800 and Apple II.

BC's Quest For Tires (1983).  An arcade game based on the newspaper comic strip, this game was released for the Apple II, Atari 400/800, Commodore 64, IBM PC and Colecovision(!) under the Sierra On-Line logo. 

Dragon's Keep (1983).  Designed by Al Lowe for the Apple II.  Yes, Al Lowe was once a children's game programmer!

Jawbreaker 2 (1983, SierraVision).  Another arcade game for the Apple II and Atari 400/800.  Designed by Chuckles without ever seeing the original Atari 2600 version!

Learning With Leeper (1983).  Released for the Atari 400/800, Colecovision, and Commodore 64 in 1983.

Oil's Well (1983, SierraVision).  Released for the Apple II, Atari 400/800, Colecovision, Commodore 64, and IBM PC.  It made a return to Sierra's lineup in 1990 for the IBM PC. 

Sammy Lightfoot (1983, SierraVision).  Another arcade game for the Apple II, Atari 400/800, Colecovision, Commodore 64, and IBM PC.  

Stunt Flyer (1983).  Released for the Commodore 64.

Troll's Tale (1983).  Another Al Lowe children's game designed for the Apple II.

Wall War (1983, SierraVision).  Atari 400/800.  The game has been called the worst ever published by Sierra.