While I played most with my main (Hecarim) my most exciting moment was with AD Malzahar.
Team was losing pretty hard. I personally was about 4/12 and the enemy team was up a LOT (over 20 kills) and was pushing in our base trying to take an inhibitor turret. Despite the bad score, I had been doing what AD Malz does - teleporting to turrets and pushing them hard with my voidlings, so bot lane was pushed to the inhibitor turret. I noticed my team was defending okay at the inhibitor turret already when I respawned, so I teleported to the minion wave approaching the inhibitor turret bot lane.
Solo'd the inhibitor turret.
Took the inhibitor.
Their Alistar managed to get there (can't remember if he teleported, recalled, or respawned) and one of my allies (Sion I think) teleported down to join me. I managed to bait Alistar's ult before ult'ing him to get the kill. At this point the enemy team managed to get out of my base and start recalling, and all my allies teleported to their base. I then took my voidlings to the nexus turrets and took both turrets and the nexus while Sion and Nasus peeled for me.
Cheesy backdoor win. Was just really impressed with myself after having such a bad game to spot the chance to steal a win.