Contra and FFVII. I would throw in the recent Hard Corps and Portal 1 and/or, but as they haven't stood the decade+ and still awesome test of time yet, I can't elevate them to mythological status just yet. I used to be more of a FFVIII guy, but within the last five years or so my love of VIII has started to wane, while I enjoy VII more than I did when I first played it.

Contra on the other hand has been effing incredible since I knew what a controller was.