Any EA NHL game, I cannot be beaten in console vs that is. Online is shit due to connection issues. We used to have huge tournies and I could only play if I used the shittiest ranked team. Which I always found funny.
Back in Star Craft 1 buddy and I were 300 something wins and I think 5 losses, we were a mean Protoss / Zerg combo.
UFC Undisputed 2009. I had over a 200 win fighting streak going after losing my first 10 fights before figuring out how to submit mofos and how to get out of them. Used a glove on my left hand because rotating the left stick so much for the submissions was giving me huge fackin blisters rofl.
I was also a beast in WWF / WCW N64 games. Never lost a tourny.
For the last of my WoW time, I had an Enhance Shammy that couldn't be beaten in the charts, I would join guild raids who needed a PuG dps, they would be all decked out in top notch epics, I would be in blues, and still out do em. I took great joy in turning down there guild offers.
Those were all moments in time when I was on top of my gaming, but by far, the game I was most godly and untouchable was Ultima Online pre Trammel (once they really noobproofed Trammel). I was a disarming thief mage who could steal any weapon I disarmed, I had so many bounties on my head from guilds I robbed it was halarious. A lot of fun 10-13 years ago when I was 15 lol.