Source: http://www.theoldcomputer.com.Bank Panic, © 1987 Sega. License: All Rights Reserved.

"The ITC Modern No. 216was used for the system's logo and packaging of the console. Most of the initial game packaging also used the typeface, creating a cohesive identity for the brand. To our contemporary eyes it seems odd to see a bookish serif promoting video games, but tightly spaced, large x-height serifs were commonly used in the '80s for every kind of high-tech product. (See Apple.)

Later, the type in the logo switched to a wider, small-size-optimized version of Century and the game titles replaced ITC Modern 216 with the much bolderPistilli Romanor their own branding.

P.S. The Sega logo was likely custom drawn, not made from a font, but similar forms can be found in Yagi Double.

Source: http://atariage.com."Chopper Commander" on AtariAge. License: All Rights Reserved.

Source: http://atariage.com."Chopper Commander" on AtariAge. License: All Rights Reserved.

Source: http://www.theoldcomputer.com.Fantasy Zone, © 1986 Sega. License: All Rights Reserved.

Source: http://www.theoldcomputer.com.Kung Fu Kid, © 1987 Sega. License: All Rights Reserved.

Source: http://www.theoldcomputer.com.Space Harrier, © 1987 Sega. License: All Rights Reserved.

Source: http://www.theoldcomputer.com.Super Tennis, © 1986 Sega. License: All Rights Reserved.

Source: http://www.theoldcomputer.com.Wonder Boy, © 1987 Sega. License: All Rights Reserved.

Source: http://rover.ebay.com."cartridgesgalore" on eBay. License: All Rights Reserved.

The Ninja, © 1986 Sefa. License: All Rights Reserved.

Source: http://www.theoldcomputer.com.Action Fighter, © 1987 Sega. License: All Rights Reserved.

Source: http://andydecarli.com.Fantasy Zone (later edition), © 1986 Sega. License: All Rights Reserved.

Source: http://rover.ebay.com.License: All Rights Reserved.