I don't know if this is still available on the shelves of retailers, but a few months ago, I bought this small portable system by Coleco (that old toy company that made the Colecovision in the early 80s) that had over 20 Sega Master System and Game Gear games built right into the system. It was on clearance, I think I spent less than 10 bucks for it, so it might be hard to find now, or it will be. Anyway, if you can find it, I'd suggest picking it up. It's just classic gaming action on the go. Some of the games haven't aged that well, but just being able to play Columns again makes it really worth getting. Columns was a Sega puzzle game that was popular on Genesis and the Game Gear back in the day; I loved it, I think it's much better than Tetris. This has the Game Gear version, which is my personal favorite.
I remember having a Game Gear back in the day, and at one of my first jobs, a hotel, I remember hiding in an empty meeting room for hours and playing Game Gear in the dark. And this game can sink you in. I know it's gonna happen all over again, and it's very bright, so it's perfect to get into a game. It also has Super Columns in it, which I've only played once but it seems like a pretty good game. A couple of Sonic games, Altered Beast, Fantasy Zone, and a bunch of SMS games are included. So if you can get it, definitely do so.