Like ever? In all of D&D?
A 2nd Edition halfing thief named Koric Dromen.
Was my first time ever at a table, but it was a good group of guys. We played pretty regularly, about twice to three times a week for two years. Took him from level 1 to 17.
It was weird being around the "seasoned professionals", who were concerned mostly with the legalities and rules for a build while I was the one asking if I could over-turn the bar table and use it as cover to hide (to backstab someone the next round), and shooting the rope on the chandelier in the desecrated church to drop it on the bad guy.
The most noteworthy feat he ever accomplished was killing an irredeemably insane gold dragon in one attack (we were good-aligned also, but the story required it to die).
We figured out it had killed a warlord and was ruling his lands in human form and was using his keep as it's lair. We all marched in convinced we were going to die and I convinced them to let me have the opening shot. I rolled a 19 to sneak up on it, DM random rolled and it was actually asleep, I made a called shot to it's eye, and rolled a natural 20 (and we used to rule that if that happened, you double your weapon damage and THEN apply your backstab multiplier). I also had a Dragonsbane Shortsword, but I didn't know this at the time (it was a gift from an NPC I saved by accident. I just used to call it "Lucky"). It was also already down some random amount of HP that the DM had pre-rolled, but he was so pissed that I ended his epic encounter outright he wouldn't tell me.
Afterward, when the group was divvying the horde, Koric announced it was time for him to go, thanked them for everything, and promised never to forget them. Then walked off down the road into the sunset. I thought that was a great ending for the character and I never played him again.