I really want to buy a Sega Game Gear--despite the fact that I only want to buy one game along with it.
That game: Magical Puzzle Popils, which I'm pretty sure I've mentioned on more than one occasion. (Yep, here and here.) I know, I could easily continue playing this Fukio Mitsuji-developed title via emulation if I really wanted to, but I'd prefer to own the real deal if at all possible.
There are a few other Game Gear titles I'm at least mildly interested in, of course--like Fantasy Zone Gear, Madou Monogatari I, II and III, and Shining Force Gaiden--but I likely wouldn't even consider picking up the system if Magical Puzzle Popils weren't available.
To make things even worse, I'd love to buy one of the rare, white Game Gears--like the one seen in the photo above--that only saw the light of day in Japan. Thankfully, even I have my (spending) limits. So, black it will be--should I ever buy one, of course.
See also: Other reasons I could be considered an 'eccentric' (aka bat-sh*t crazy) gamer