Call of Duty 4: Modern Warfare - Probably the most influential shooter of my teen years, I distinctly remember it being the one big beta that everyone wanted to get into at the time when I think there wasn't many public betas going around and playing the full game non stop for what felt like eons but was probably only until Rainbow Six: Vegas came out (Almost made it onto my list in its own right) Vacant and Backlot were so ingrained into my memory I was able to pick up where I left off when isolation afforded me the opportunity to get into the new MW and not be completely shit from the off
Fallout 3 - Ah yes, My one true love. Might be slightly biased as im currently in the process of replaying this now but it definitely deserves to be here on it's own merits, Despite the obvious played it a whole bunch it sparked a long running obsession with the series for me that obviously continues to this day, Anyone that visits my home now is quick to notice my Fallout shrine, Mini-Nuke, Pipboy and all. Also lead to a lifelong friendship, Which as I get older I realize holds a lot more weight then it probably sounds written here.
NASCAR Racing 2003 Season - A weird one to be sure but during my depressive teen years I logged literally thousands of hours on this sim, Practicing for and competing in league races every week just to make it through every week, In addition to that it also changed my life dramatically, I honestly don't know where i'd be had I not met my first housemate through this. Another lifelong friend met through games. goddamn. But despite me getting rid of my wheel years ago this is still one I wish I could hop on to this day, Especially considering all these pro drivers running in these iRacing leagues (the spiritual successor to NR) during the sports downtime.
Smackdown: Here Comes the Pain/EWR - I can't pick between the two and this is a wrestling board, Shut up 😒
Pokemon Gold - I'd gamed plenty as a kid sure but nothing caught my imagination like Gold did, I vividly remember getting it prior to a camping trip so I wouldn't bother the adults and falling prey to the classic "play it via street lamp light as they fly by". The actual grind of all grinds to level up my Feraligatr to 100 before the days of exp share was a early highlight of mine, Basically being able to slap down anything I fought in one hit.