I've been wracking my brain trying to remember...
I think it was Legendary Wings for the NES. Picked it up at the local flea market in Raleigh. I want to say it was about $4 or so; I must have been 8 or 9. Had never heard of it, only got it because the label art was interesting and I wanted something new. I really enjoyed it!
But I must say, my most memorable game pickup was around that time at Rose's (or was it Roses?). My mom said I could get a new game as long as it didn't cost too much. I didn't really recognize any on the peg hangers (how times have changed), but there was this one that caught my eye - Bionic Commando. I don't know that I had ever heard of it; might have read about it in Nintendo Power or some other gaming mag. But I did recognize the publisher logo: CAPCOM. I knew them from Mega Man, the first game I ever rented and played in my own home.
In the following weeks I was addicted to Bionic Commando. I even faked being sick to stay home from school and church. My parents found out, though, because one Sunday I put on my routine, I got stuck in one of the areas...the one with the barrier at the beginning and I think you need the rocket launcher to get through. The internet being about 10-11 years away, I called the Nintendo Game Counselors - a few times that morning - and then when the phone bill came in they saw calls on that day to Redmond, WA. The only disciplinary action I can recall is some stern words and maybe a threat to lose NES privileges if I did it again.