I had somewhat of an ordeal acquiring a Game Boy Advance in the last few months. Rose Colored Gaming is sold-out (they can no longer acquire back-lit screens for GBAs), I also had no luck on Craigslist, a few used video games stores had nothing available; it was almost enough to make me quit!
I had to resort to eBay to buy a GBA SP-101 model, the only Game Boy Advance with a back-lit screen that could also play Game Boy and Game Boy Color games (you’d think the Micro or even the DS Lite had the same backwards compatibility, but they only cater to GBA games).
Unfortunately my GBA has no headphone jack, and its form factor is a little awkward to hold at times, but it’ll do for now.
Given the apparent scarcity of quality Game Boy handhelds, and the flaws of all existing models, I’m hoping a third party company (like Hyperkin) decides to offer a brand-new Game Boy that covers all the bases.
Features-wise all I’m asking for is a big LCD screen, GB/GBC/GBA compatibility, charging via mini-USB, and an audio jack. As for the design, I think a clamshell approach like the DS/3DS handhelds is best (saw a lot of scratched-up screens in the past few months). For fun I put the cartridge port in the front, so you can always see what’s in the slot (also it looked a bit too plain without a second screen there).
If you wanted to go really overboard, you could include 2 cartridge slots for alternating between games (or to just transfer Pokemon between game paks).
This new Game Boy would be the perfect companion to the 3DS; between the two of them you’d cover all generations of Nintendo handheld devices (minus the Game & Watch handhelds, of course).
Note: yes I looked extensively into handheld emulators, but aside from the PSP the pickings were slim. What can I say, I prefer the plug-and-play of a cartridge pak.