Oh oh! Here's one that I lost... but it's super crazy!
Top 2 in a Cities Championship this season. I played Steelix and faced deck after deck with Blaziken FB techs (if I remember correctly, I played 7 opponents in all, 6 of which played some fire tech in their deck capable of one-shotting my Steelix). My top two matchup was against a good friend of mine playing Luxchomp with the Blaziken FB tech. My Steelix runs an SP Quagsire tech to deal with it, but even with the tech a 1-1 Blaziken tech is still super hard to deal with.
The balance of the games gives and takes, with my Quagsire actually giving me a chance to win. Near the end of the game, I have the choice of either using Gaia Crush to KO a Pokemon (and therefore leaving me vulnerable to Blaziken) or using Energy Stream to pull another Special Metal onto the Steelix. It's a pretty important decision, so I count the number of Crobat G's, Poketurns, and possible Junk Arms my opponent has left to aid in knocking out the Steelix. After about a minute of counting, I finally announce my attack: Energy Stream. I know I made the right play cause my opponent lets out a sigh. My undamaged Steelix will actually be able to survive Blaziken's attack! My opponent brings the Blaziken up and swings for 160 (minus damage for the Metal Energy). I look down at a hand full of Moomoo Milk and Life Herbs that I saved up.
Before I go on with the rest of the story, I should tell everyone that I am TERRIBLE at flipping coins. I'm also pretty good at not believing in the "myth" of bad luck (woe is I and only I!), but many of my friends who play with me can vouch that I just can't flip a heads to save my life.
So yeah, with 2 Moomoo Milk and 2 Life Herb, I manage to flip all tails. My Steelix HAS to survive, so I count up all my cards and realize that I have a single Life Herb remaining in my deck of 6 cards. My hand is now depleted except for a couple of cards, including a Volkner's Philosophy. I don't want to deck myself and I still need to take 3 prizes, but I have to hit that Life Herb this turn (there's a Garchomp X staring me down from the other side of the field). So I count again... and again. I know my deck inside and out, so I deduce that I have 1 Judge and 1 Bebe's Search remaining between my 6 card deck and my 3 prizes. Provided that I hit one of those, I can buy myself another turn with a Bebe's or a few more turns with the Judge. I finally play my Volkner's for 5 cards, leaving 1 card. My Life Herb's there, so I play it immediately and finally land a heads. I sigh in relief, but then realize that I didn't draw into my Bebe's or my Judge. I OHKO the Blaziken, and my prize? A Smeargle. My opponent didn't even have the DRE for the Garchomp X and draw/passes. My last card in my deck? A Basic Metal.
Yes, the Bebe's Search and the Judge were my remaining two prizes. As I realize that I've decked myself, I have to laugh it off. It was my goal to win that one tournament with Steelix even though I faced autoloss after autoloss (seriously! I faced one opponent playing a 2-2 Blaziken FB/Victreebel deck who only attacked with Blaziken and cycled it in twice with Aaron's Collection... still managed to win that one somehow), and I just decked myself with the worst of luck. I take my second to last prize and tell my opponent good game since I have no cards remaining in my deck.