Wow going over these comments it seems most of my choices have been taken. Well played, internet. But there is one that is suspiciously absent, that I absolutely loved and haven't seen on here.
Killer Instinct.
I probably sunk more quarters into arcade machines playing that game than any other, seriously. And I own all the console versions. Killer Instinct Gold was my fav of the series, back on the N64. They keep saying they want to make it, they should just MAKE it and stop talking about it.
Also there is one I haven't seen mentioned on here, and that's probably because it was an old indie game that very few people actually played.
J.D. Spy.
That game... words cannot express how that game made me feel. I was just a kid when I first played it but it literally blew my mind. It was very VERY difficult, but I went through it anyhow. A sequel for that would be so great. I do believe J.D. Spy is freeware, and I encourage you to find and play it.
I mean how many games crash on you when you first boot it up, but the crash is much more than it seems...