The Game Gear came in two versions: One produced by Sega and one later re-released by Majesco. The latter does not support the system’s TV tuner (which would no longer work with modern airwaves anyway) nor the Master Gear Converter which allows the system to play Master System games.
Functionally, the units are otherwise the same save for almost unnoticeable aesthetic differences.
The Everdrive GG X7 is a classic flash cart, which enables owners to load Game Gear ROMs to an SD card and, thanks their small file size, fit the console’s entire library into one cartridge. This unit provides instant loading, low power consumption, and also supports Master System games.
The Game Gear wasn’t exactly known for its screen, which, while impressive in 1990 for being technically back-lit and technically color, is dim and dull by today’s standards. Therefore, a screen replacement is one of the more common mods for the system.
We recommend using the McWill screen replacement which doubles the system's resolution and scales the image to fit the bright, colorful new screen. As a bonus, it also enables VGA output from the console to a TV or monitor.
(It also can’t hurt to replace your unit’s screen lens while you're tinkering around in there. A glass lens will show less wear and tear with regular use.)
The Game Gear famously chewed through considerably more batteries than the Game Boy. If you plan on taking it anywhere, buy six (yes, six) of your favorite rechargeable AA batteries. We recommend Panasonic’s Eneloop line.
So, here’s the thing. The capacitors on Game Gear consoles are notoriously bad and known to need replacement on even lightly used consoles. Whether you do it yourself or send the unit out for third-party service, you’re going to have to get these replaced.
(While you’re at it you might as well spruce the system up with colorful replacement buttons and replace the battery compartment door lid covers, which tend to scratch.)
We legally can’t tell you how to procure ROM files for Game Gear games. On an unrelated note, Archive.org is a nice website that many people like using.
We recommend: Gunstar Heroes, Baku Baku Animal, Columns, Streets of Rage 2, Wonder Boy III: The Dragon's Trap, Sonic the Hedgehog 2, and Sonic Drift 2.